When a Phillips Is Not a Phillips Plus So Much More!




Introduction: When a Phillips Is Not a Phillips Plus So Much More!

When a Phillips is not a Phillips - Plus So Much More!

A Continuation of Screws and Drives

by Egon Pavlis, Biomedtronix Inc.

With overwhelming response to my preceding "ible" titled "When a Phillips is not a Phillips? - Cross-head, Cross-Point, Cruciform, Square Drive Screws and Drivers" and this logical expansion follows. Readers requested information on all - recessed screw drives including security, especially the tougher ones to find. Well, here they are.

This article contains a lot of information presented from company websites, catalogues and brochures and so 'may be biased' to highlight their drive qualities. There are some advantages and disadvantages of some drive types. This "ible" is not intended to present one drive superior over another as each has desirable qualities. Maybe it will be the definitive guide with your help it could get close.

If you disagree with any of the information or if I missed a related drive you know of, please let me know where I can validate the information. Miss-information, incorrect illustrations, screwed up usage of terms on the Internet and elsewhere is rampant and part of the problem created by so many drives.

Should you have relevant information, especially verifiable or with web links, clear pictures etc to add, correct or improve the project please email it to me so I can follow-up on it.

Please refer to the Step # when leaving comments or questions to that specific drive types. 

Use this project, enjoy it, share it, just do not claim it as your own or sell it. Some of the contents have been borrowed, copied, clipped, etc and may still be copyrighted by others.

Should you feel motivated enough to forward cash $$, I'd like to inspire and encourage you to please remember I like and also collect all flavours of world currency!

If you enjoy this work, please remember to Vote accordingly if you see it in an Instructable Contest.

  • Notes about project layout
This "ible" is presented with one screw drive type per step. When possible there is a head icon pattern, a drive bit or tool picture, plus additional pictures and text to help clarify the type. The order of types presented is based somewhat on the shape; number of corners, points or drive surfaces; number of ways to engage the drive; etc and from least to most.

Icon patterns of each screw type are a view of the screw head, straight on. They can best be visualized if you imagine the screw head is used as a rubber stamp with a black inkpad. The screw head fingerprint result transferred onto white paper should resemble the icon. The drive of course is usually, but not always, an inverse of this. Occasionally gray is used in some icons to indicate detail at a different level, one that would also not touch the black in the print, but requires the detail highlighted.

A few types are grouped at the far end of the 'ible', these include Combo Drives, Security Key Drives and Gamer Drives.

Step 1: First a Little Background

So, why all the confusion then?

Why all the damaged screw heads and drivers?

Why is this screw and driver thing so awkward?

Read on and be amazed while unraveling the mystery of screw drives and present some you may have never seen. Seems everyone with an idea tries to patent a new screw to get rich, many just do not make it.

Today screws are everywhere and many are more easily confused than ever before. This guide should help you through many kinds. Let's us cover some basics and a bit of history first.

So what is a screw?
A screw is really a shaft with at least one helical groove (thanks tallmanbaby for reminding us that with today's screw products a screw could have more than one groove) or thread formed on its surface. Its main uses are as a threaded fastener used to hold objects together, and as a simple machine used to translate torque into linear force. It can also be defined as an inclined plane wrapped around a shaft.

Every threaded fastener needs a way of turning it. This 'Screw' driver may be a wrench that fits a hex-head bolt or a nut, or it may have a shaped and recessed hole into which a driver can be inserted.

Step 2: Early Screws

Wooden Screws
Around the first century, screw shaped tools became common, however, historians do not know who invented the first. Early screws were made from wood and were used in wine presses, olive oil presses, and for pressing clothes. Turning the screw was accomplished with a drive rod handle positioned through the perpendicular hole.

Metal Screws
Metal screws and nuts used to fasten two objects together first appeared in the fifteenth century.

In 1770, English instrument maker, Jesse Ramsden (1735-1800) invented the first satisfactory screw-cutting lathe. Ramsden inspired other inventors. In 1797, Englishmen, Henry Maudslay (1771-1831) invented a large screw-cutting lathe that made it possible to mass-produce accurately sized screws. In 1798, American David Wilkinson also invented machinery for the mass production of threaded metal screws.

In the picture with 3 old screws, the screw on the left (A) was handmade in the late 18th century. Note the flat spot on the shaft, the irregular threads, blunt tip and the off center slot. The screw in the center (B) is machine made around 1830. It has sharp, even threads, a cylindrical shape, blunt end and the slot is still off center. The screw on the right (C) is a modern gimlet screw, post 1848, with tapered shaft, even threads, pointed tip and centered slot.

Step 3: Security Fasteners

There are basically two types of security fasteners - tamper-proof and tamper-resistant. Several tamper-resistant drive types were created and were originally intended to be tamper-proof. See the "Tamper-Proof Screw Myth" below.

Tamper-Resistant Screws
Most security fasteners including Phillips, TORX®, and Hexagonal, are also manufactured in tamper-resistant form. These are screws, bolts, nuts and fasteners that are difficult to remove but not as unique in design and application as the tamper-proof fasteners. They offer a good level of security because a special tool other than your standard Phillips or slot-type screwdriver is needed to remove them. They are also very popular as they can be purchased in small quantities from most security parts distributors and are considerably cheaper than tamper-proof fasteners.

However, the bits for many tamper-resistant screw heads are now readily available from hardware stores, tool suppliers and through the Internet. There are many commonly used techniques to extract tamper resistant screws without the correct driver, like using an alternative driver that can achieve enough grip to turn the screw; modifying the head of one drive to work on a tamper-resistant drive, and others. These special screws offer only modest security.

Tamper-Proof Drives
There are specialty fastener companies that make unusual, proprietary head designs, featuring matching drivers available only from them, and only supplied to registered owners. An example of this would be the attachment for the wheels and/or spare tires of some types of car; one of the nuts may require a specialized socket (provided with the car) to prevent theft. Some examples of these fasteners are Uniqz®, Keyed-Lok® and Penta-Plus&reg tamper-proof fasteners from Bryce Fasteners.

The Tamperproof Screw Myth
Tamperproof screws are not as tamper proof as people think. Beyond marketing claims, most drive styles are no longer really tamper-proof. The reason is that most security screw bits have become easily obtainable, and there are tens-of-thousands in circulation. Seems almost everyone has some.

Security screws have been in existence for 50 years and most are without patent protection. "Tamperproof" bits are being manufactured, imported, and widely distributed, without restraint. There are many thousands outlets and catalogues in circulation marketing security bits and with this ease of access it has made Torx-pin®, Hex-pin®, Phillips-pin®, Spanner, Triwing®, Tri-Groove®, Gamer screws and One-Way screws "vandal-proof" only. "Tamperproof screws" are mostly a myth.

Pin type screws can usually be removed by using a hammer and an awl/nail/knife/etc and knocking the pin one way and then the other until it snaps out, thus leaving you with the non-security version.

Step 4: Non-Slip Fluids

Before visiting screws you should be aware of Non-Slip Fluids. You may not be aware these products are even available (like me).

'''ND Industries DriveGrip Anti Cam-Out Fluid®'''

ND DriveGrip® makes removing or tightening screws and other fasteners a breeze. A single drop of DriveGrip® creates a positive grip between the metal surfaces of the fastener head and tool. Works great in applications where fastener heads or drives are worn or damaged. ND DriveGrip® increases the grip strength between the fastener head and tool by as much as 700% and virtually eliminates tool wear, rounding, and deforming fasteners.

ND DriveGrip® helps you remove rusted or "frozen-in-place" screws and bolts that wont budge. Use ND DriveGrip® in conjunction with all types of screwdrivers, hex keys, pliers, channel locks, vise grips, as well as open-end box-end wrenches.

'''Align-Rite Ltd's ScrewGrab®'''

ScrewGrab® is a friction gel that helps remove or tighten all types of fasteners - damaged or rusted. A single dab of ScrewGrab® creates a positive grip between metal surfaces (new tests have shown as high as 800%), that virtually eliminates tool wear and the stripping, rounding or deforming of fasteners.

ScrewGrab® is not a Glue and works instantly, wipes clean after use, is non-corrosive and has an unlimited shelf life. Useful on stripped, rounded or deformed heads, seized, rusted, or hard-to-reach spots. Works on sloppy or mismatched sockets and stops bits from turning in chuck.

'''EZ Grip Friction Drops™'''

EZ Grip Friction Drops™ come in three different grades: commercial, aircraft, and marine. In the commercial and aircraft grade drops, the alumina cubes are suspended in a non-toxic, food-grade antifreeze. The aircraft grade meets five different ATSM and Miltary standard tests. In the marine grade, the hardened aluminum cubes are suspended in a blend of non-toxic oils instead of antifreeze.

The next time you are struggling to remove a screw with a damaged head, instead of reaching for a screw extractor, you might want to give EZ Grip Friction Drops™ a try. The manufacturer claims that one drop on the damaged screw head will increase the gripping force enough to remove the problem screw. Their secret? Thousands of hardened aluminum cubes, each 4 microns in size, suspended in a carrying agent give EZ Grip Friction Drops™ gripping power. The aluminum cubes provide a temporary bridge between the tool and stressed fastener heads.

Step 5: Pliers Designed to Extract Damaged Screws

These pliers may also be worth considering when removing stubborn screws.

Got a stuck screw or a screw with some wacky security head? "Do not reach for the extractor kit; wrap these $25 screw pliers around the head, and simply twist the screw out." Is the claim made by a leading Japanese hand tool manufacturers - Engineer Inc., formerly Futaba Tool Mfg. These pliers remove tamper-resistant, rusty, stripped-head, or otherwise damaged screws. - a Toolmonger review by Benjamen Johnson

Step 6: Round Head With Blank Head

I accidentally found this unique drive head system while working on the original Phillips project and since it did not apply there have since lost the specific information and the links. The remembered information is that it was a Japanese news article (google translated the webpage from Japanese) discussing a recent invention. The screw head has no markings and is round and blank. The screw head mimics a rivet, to discourage vandels. The driver utilized a heated ceramic head that when heated and the screw head expanded the grip would be tight enough to drive the screw. Once cooled the screw became virtually tamperproof unless heated by the same driver head unit.

Step 7: Oval Head Security Screw

Oval Pan Head Security Screws are unique in the sense they have no conventional drive slot in the head. The screws must therefore be installed or removed using a special recessed driver that precisely accommodates the oval head. This unique feature renders the Oval Pan Head Security Screw vandal-resistant, reducing the risk of vandals or intruders tampering or undoing the screws. The head gives a deceptive appearance, looking like a stud or rivet. Due to the design of the Oval Pan Head Security Screw it is suitable for low to medium torque applications and is "2 way".

The special hand driver is available in two sizes - OP4 for M4 screws and OP56 for M5 and M6 screws

Step 8: Avsafe™ Screw Drive

One type of security fastener is the slotless, tamper resistant Avsafe™ Series FP/FR/FG screw marketed by Avdel Corporation Systems Division, Parsippany, N.J. Security fasteners such as the Avsafe™ Screw typically include a threaded shank connected to a slotless oblong head designed for installation and removal with a special drive tool and cannot be turned with an ordinary socket, hex head wrench or other conventional tools.

One arrangement for preventing such tampering is to locate the security fastener within a recess in the panel. The sides of the recess must be spaced far enough apart to allow the special drive tool to fit but too close together to allow other tools such as pliers from grabbing the head of the fastener. These recesses increase the cost of manufacturing and are not desirable for some installations.

Step 9: Off-Set Pin Tamper Resistant

This fastener includes a round, blind hole or pocket in its head. Installation and removal of the fastener is accomplished with a tool containing an eccentric segment on the end of a shaft. When rotated within the pocket, the eccentric segment displaces laterally relative to the shaft to provide a friction grip to the lateral wall of the pocket. The strength of the grip is proportional to the applied torque. Eccentric displacement allows rotation but prevents the tool from spinning out of the fastener thereby eliminating cam-out and surface damage resulting from contact with a spinning tool tip. The eccentric head of the tool can be made disposable and to shear off when a predetermined torque is reached. The smooth-sided round hole offers no purchase for commonly available tools; making the fastener tamper-resistance. In another embodiment, the fastener includes a raised portion in the pocket. A tool having a complementary opening shears off the raised portion at a predetermined torque. United States Patent 7066062

Step 10: Keyed-Lok® Security Screws

The Keyed-Lok® Security Screw, by Bryce Fasteners, have a pin within the unique shaped socket of the head requiring a special insert bit to insert and remove, making it more like a lock because it requires a perfectly cut tool or key to operate it. There are millions of keyway variations to ensure that each key code is exclusive to the owner. These drives are not mass produced bits sold indiscriminately by the thousands, it is a high security locking system. Only the owners have their private or exclusive key code.

Unlike Hex or Torx screws, it does not have symmetrical shapes that are easy to distinguish and compromise. Keyed-Lok® is not an easy target or false security. They are not just a tamperproof, vandal-proof, tamper-resistant screw, it actually repels Hex, Torx, Slotted bits and even Vice grips. Due to the design it is suitable for medium torque applications and is "2 way" re-usable security fixing. Least expensive high security tamper-proof comes in more sizes from 3/56(M2) to 5/8-11(M12)

Step 11: Spin-Lok™

Spin-Lok", from Bryce Fasteners, is a tamper-proof screw for applications requiring permanent installation. Spin-lok" is configured so that the bit intentionally rounds out the socket at a precise torque. The result is a perfectly round hole with a center pin. Torque is calibrated within 1 inch/lb and set to the customer&aposs specifications.

Benefits include being less expensive; rustproof (made of solid stainless steel); easy to install with the correct bit (can be inserted with power tools) and is available in sizes 6/32 [M3] to 1/2-13 [M12] screw diameters.

Step 12: Slot Type Drive

Cutting a slot in a screw head to turn it is an old idea: drawings from the 16th century show screws with slotted heads.

The advantages of the slotted head are that: most people have a screwdriver that fits them (sort of); worn drivers are easily reground; a new screw head slot can easily be cut with a hacksaw. Otherwise the slotted head is the worst screw drive system, and while very common, it is also generally obsolete. Some of its deficiencies include: the driver does not automatically center or line up with the slot (there is a picture of a driver tip that helps keep the driver on slot); it is easy to get off center; the user must keep the axis of the screwdriver aligned with the axis of the screw; the driver can engage the head in only two possible positions, at 180 degrees. The sides of most slotted screwdriver bits are tapered. When the driver is turned it tends to be pushed up and out of the screw head. This is called "camout", see glossary.

To add to the shortcomings of the slotted head, screwdrivers for slotted screws are usually described by the length of the shaft and the width of the tip; the crucial measurement, the tip's thickness, is rarely given. Any given tip width is sold in a range of thickness; the longer shafts usually have the thicker blades.

Step 13: ACR® Slotted Driver

This is basically a Slot Drive but ACR® (Anti Camout Ribs) technology reduces damage to screw heads while giving better drive force and improved user hand comfort. Less camout means less damage to assemblies. This driver improvement can be used on all standard Slotted and Cross-Slot Screws. For more on ACR® see ACR® Phillips®

Step 14: Stepped Slot Screw System

This screw and driver are designed to center on the screw head and not slide out. Some of the positives of the system are that it works, although rarely encountered, as it did not catch on as other more popular drive systems were developed. This drive did address some of the deficiencies of slot screws including: the driver does automatically center or line up with the slot; the screw keeps the axis of the screwdriver aligned with the axis of the screw; the sides of the driver are parallel and so reduces "camout". A secondary feature is vandal-resistance as the wrong kind of driver will not enter deep enough and may not have enough torque to remove a screw without damaging the head.

Step 15: Coin Slot

Tightening and unscrewing the coin screw is quite effortless when using a coin as a tool because of the large size of screwhead and slot. Very similar in appearance to slot head but with a rounded concave bottom to accommodate a rounded coin shaped driver deeper. Coin screws are popular for items requiring a screw or cap that may need to be removed when no access to tools, like camping gear etc.

Here is a good example of a coin screwdriver at Promopeddler, and a coin screw cap demonstrated in a Ralph Ditton review of the SteriPen Adventurer water sterilyzer from Backpackgeartest.

Step 16: Clutch Drive Type A

[[br]]See also Clutch Head Type G. Originated by United Screw and Bolt. There are two kinds of clutch head screws, the older G-style and the newer A-style. A clutch head is a type screw head and screwdriver. Unlike a standard slot screw tip, clutch head tips have four main points of contact. These lock into the screw head when turned counterclockwise and unlock when turned clockwise. This tip will not damage the screw head because of the many contact points.[[br]]

Step 17: Clutch Drive Type G

[[br]]See also Clutch Head Type A. Sometimes referred to as the butterfly shape, it is the older than Type A. Found in some trailer trucks and mobile homes. Type G Bits are recommended for: Maintenance work or applications requiring frequent removal. Applications that do not require friction hold.

Clutch head screws were popular in mobile home construction and electric motors. Chevy and GMC trucks manufactured in the 1940&aposs, 50&aposs and 60&aposs and some Corvettes had these. Frequently, the bed of these trucks used the larger 5/16" clutch head screws and the cab, dash, doors and striker plates used 5/32" to 5/16". A worn tip on a driver can easily be restored by grinding the end. The size is the diameter in inches of the bit point. 1/8", 5/32", 3/16", 1/4", 5/16"

Clutch Head were also used on older tractors to fasten the grills and sheet metal parts to the tractor, The earlier ones had a round head and there was really no way to remove them except with the special driver. Use of a regular standard screwdriver on these screws will often result in a stripped screw head. They were used in mass production drivers because it is much easier and faster to install them with a power driver than it would be if they used regular bolts. [[br]]

Step 18: Clutch Head Slot Security Screws

Clutch Head Security Screws are also known as 'One Way Screws' and are used for permanent installations. They can be installed using an ordinary screwdriver. The head of the screw has a normal drive face and a chamfered rear face which prevents the screwdriver applying torque when trying to undo the screws. Once installed these screws will typically have to be drilled out to remove them, however there is a special remover bit for these, as shown.

This unique feature renders the Clutch Head Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Due to the design of the Clutch Head Security Screw it is suitable for higher torque applications. From fellow instructable member lordzion: These screws are also referred to as Jail Head. Use is declining but they are usually self tappers, woodscrews or machine screws in applications of domestic window locks, Jail Cell hinges and exposed door lock screws.

Step 19: Spanner "Snake Eyes" Tamper Resistant

[[br]]Also known as Snake Eyes, Pig Nose Screws or Twin Hole. They have two small holes drilled into the head. A special twin pin driver bit is required to both tighten and release the screws. Spanner bits come in sizes: #4, #6, #8, #10.

Be aware there are also Metric Snake Eyes where hole spacing does not match spanner, as well the hole sizes are different.[[br]]

Step 20: Step 20: Tamper Proof Notched Spanner

This drive is similar to the 4-Notched described later.  Spacing of the pins is not critical. 

Sized include #4, #6, #8, #10, #12, #14

Step 21: T-Screw Security System

[[br]]The T-screw has a T-shaped head, with flat sides. It can be turned using the special spanner. Quite often the application T-Screws are used for is blind fastening, where the head is inserted then crossed within a channel or slot and the fastened with a nut. In one common application T-Screws are the most secure way to hang a picture. Brackets are screwed onto the back of the picture frame and the screw is inserted into the wall, in accurately measured positions. The frame is then fitted over it, and the head turned to engage the channel of the frame using a security wrench key.[[br]]

Step 22: Hi-Torque®/Speed Drive Recess

[[br]]Alcoa Fastening Systems' Hi-Torque® recess is milled into the fastener head and has a proven record of performance wherever maximum efficiency from structural fastening systems is required. The system is optimally suited in maintenance efficiency where repeated installation and removal of high strength fasteners are encountered. This cup shaped slot form serves to help the driver to auto-center, which results in timesaving and extra convenience.

During installation or removal, the inverted keystone section of the recess delivers the important locked-in condition. Rotation of the solid driver tip provides a full bearing load, and the interlocked position eliminates the need for end load by the operator. Driver reusability cycle is higher than other fastening systems. The system has sufficient torque reserve for positive and sure removal, even years later.[[br]]

Step 23: Hi-Torque/Connie® Drive Type II

[[br]]Alcoa Fastening Systems Conical (Connie®Torque® proprietary recess incorporates an innovative design that provides more ready assistance during installation to assure positive alignment of tool-to-recess. An advance beyond the Speed Drive, the high-performance Hi-Torque® has a conical recess centered on its familiar bow tie undercut shape.

Meeting all the requirements of the ultimate recess and with the full capability being installed at high torque values, the system also has sufficient torque reserve for sure and positive removal, even after years of service life. The Connie®Torque®, with its simple driving tool point and matching recess cone, assures relatively rapid and positive engagement as well as rotational alignment. Further, the seating of the blade tip into the recess holds the blade in place without the need for end load. The better alignment feature assures reduced assemble and maintenance costs: speeding the work with less chance of damage to adjacent structure.[[br]]

Step 24: Tri-Wing® Security Screws

[[br]]Tri-Wing® is a registered trademark of Phillips Screw Company. The Tamper Tri-Wing® Security Screw has a unique triangular slotted recess, which highly tamper-proof requiring a special insert bit or key wrench to insert and remove. This unique feature renders the Tamper Tri-Wing® Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. The design of the drive system is suitable for medium to high torque applications and is "2 way". Tri-Wing® sizes include: #1, #2, #3, #4

Nintendo used these screws on several consoles and accessories, including the Game Boy, Wii, and Wii Remote, to discourage home repair. See Gamer Drives.[[br]]

Step 25: Opsit® Security Screws

[[br]]Opsit® are a registered trademark of Tamperproof Screw Company, Inc. An interesting concept for tamperproof screws is the reverse thread sheet metal screw that installs counter-clockwise, thus, tightens if removal is attempted. Off-angled blades allow more insert torque than removal torque. Very tamperproof as the bit is not easily made. [[br]]

Step 26: Tamper CELOK® Security Screw

[[br]]The Tamper CELOK® Screw has a constant trilobular geometry making the recess highly tamper-proof, requiring a special insert bit or key wrench to insert and remove. Due to the design of the vandal resistant Tamper CELOK® Security Screw it is suitable for medium - high torque applications and is "2 way". [[br]]

Step 27: Tri-Groove® Tamper Resistant

[[br]]Slots in the outer edge of the head provide a more positive drive with less risk of fastener distortion and breakage. Power-driven equipment may be used with the matching driver socket, making this model suitable for mass-production applications where both a high level of security and fast assembly time are required - eg. electronics or office equipment.

Step 28: Uniqz® Tamper-Proof

[[br]]Designed specifically to give the utmost protection from theft and vandalism, Uniqz® is said to be the ultimate security fastener which became Key-Lok® also by Bryce Fastener. An affordable, practical solution for loss-prevention applications in the electronics industry, the product has the benefits of a combination lock in the head of a screw. A patented three-sided, recessed head design is custom-fabricated and licensed to individual users. Each side of the head has the potential for 20 different degrees of angle and 20 different depths of recess. This number amounts to more than 16 million unduplicated driver configurations, said to be more than a front door key. These fasteners employ a specialized screw driver bit, or key with each bit having its own unique, 12-digit combination code. The user inserts the key into the head of the screw and twists it until the combination matches and falls into place. Unlike standard tamper-resistant fasteners, these bits cannot be obtained in hardware stores. [[br]]

Step 29: Holt Head Tamper-Proof

[[br]]This patented drive provides the perfect tamper-proof assembly. Theft-proof and decorative, yet inexpensive. Special drivers available for field removal or power driven assembly machines. The unique tri wing slots starting out from the center and are sloped and not flat perpendicular to the drive.[[br]]

Step 30: TORX® 3-lobe

[[br]]Torx 3-Lobed screws and screwdrivers that have triangle-shaped sockets and heads are used in the Netherlands and cannot be found in North America. (Not at all sure of the icon or the information, need confirmation on this, as I could not find out much).[[br]]

Step 31: TP3® Triangular Recess Security

TP3® is a new triangular recessed drive offers great security. You may be able to make my own by filing down a 6-sized hex bit, but they never fit or work very well. These security bits are being used on an increasing number of products; Nintendo, Gameboy; Fast Food promotional toys and video games; Die-cast toys; Roomba battery packs. There are four sizes; A=0.079" A=0.091" A=0.106" A=0.126". See Gamer Drives.

Step 32: Triangle-Pin Tamperproof

[[br]]Not much information on these available but basically a solid triangle recess but with a pin center. Very difficult to make a tool for this which gives it a tamperproof rating.[[br]]

Step 33: Exterior Triangle Head

[[br]]Not many tools will work on this tamperproof screw head without damaging it. Uses a driver socket with triangle hole. Simple but so effective.[[br]]

Step 34: Secufast® Tricle

[[br]]The Tricle Re-usable Security Screw has a unique pin recess design making the recess highly tamper-proof, requiring a special insert bit or key wrench to insert and remove. Tricle requires a special driver bit and is suitable for medium - high torque applications. Screws come in sizes M3, M4, M5, M6, M8 and M10.[[br]]

Step 35: Tri-Arc®

[[br]]Tri-Arc® is a new concept in screw head, a bits and driver design that has been comparatively tested to Crosshead design. The head has a recess that consists of three lobes. The recess is based on each lobe separate by curved drive flanges. The driver has a drive tip that fits the recess of the screw or fastener and sinks 2-3mm below the surface of the upper flange. The 3 curved surfaces give Tri-Arc® screws and fasteners more contact surface area and more surface pressure area.

The main advantages of this new design include increased resistance to cam out and reduction in wear and tear on its drivers compared to the Philips or Posidrive. The bit doubles up as a good countersinking tool.

These may not be on the open market as yet, as the inventor is requesting a company who can develop the product and/or is interested in a licensing agreement. [[br]]

Step 36: Trigram® Screw Drive

[[br]]Trigram® screws and drivers have a flat end, unlike the Tri-Wing®. The sides are tapered to prevent non-designated drivers from proper seating and therefore the sides encourage camout.[[br]]

Step 37: Microtech® Pin Screw Drive

Microtech® Knives use an exclusive Terzuola screw with recesses for 3 or 4 pins drivers. Outside diameters of all screws may vary on different styled Microtech® knives, however, pin size should remain the same. There are 3 sizes of drivers; Small - fits handle screws that have 3 holes; Medium - fits handle screws that have 4 holes (If the knife was made after 2006 it may not have the center hole.) Basically if another hole would fit in the middle of the outer 3, it is a medium; Large - fits the pivot screw on MT side openers and some belt clip screws. Current production wrenches have no center pins so they can be used on the new style screws.

Pictures used are copywritten by Microtech.

Step 38: Tampruf®

[[br]]Tampruf® is Australian and refers to both screw heads and nuts. Rather than the regular bit tips for drivers, these use a socket drive system.

Tampruf® 1/4" Square drive sockets come in at least 3 sizes; #4 socket fits #4 round head and #6 counter sunk head; #6 socket fits #6 & #8 round head, #8 & 10 counter sunk head; #10 socket fits #10, #12, #14 round head, #14 counter sunk head.

Tampruf® 3/8" Square drive sockets come in at least 3 sizes; #20 socket fits 5/16 round head #10, 1/4 nuts; #30 socket fits 5/16 & 3/8 nuts; #40 socket fits 1/2-13 nuts.[[br]]

Step 39: Scroll™ Nuts & Screws

[[br]]Tamper resistant, releasable Scroll™ Nuts and Scroll™ Bolts are the ultimate security fixing. They offer a clever solution for those situations where you need an anti tamper fixing that can also be undone when the need arises. The Scroll™ Nut or Bolt is installed and removed with the aid of a special driver tool. The 1/2" drive security driver is cross drilled with a hole that allows it to be used with a 'T' bar or a standard socket drive set. The tool to match the Scroll™ Nuts and Bolts are registered to the owner adding additional security.

The special grooves cut into the outer surface of the scroll nut accommodate the special driver lugs in the recessed cup to allow the nut to be tightened or released. As a special manufacturing option, the scroll nut can also be made with just a drive groove, converting the nut into a one-way unit which performs in the same way as a shear nut. Sizes available in even numbers M6 to M12 and Tool Reference in even numbers SC6 to SC12.[[br]]

Step 40: Cross Slot

[[br]]Double-slot cut screw heads, with cuts offset by 90° and is rarely used or seen today. The advantage of this type of screw head is there are 4 ways to engage the screw. Screw heads need to be thicker and harder to accept the drive. Otherwise all other advantages and disadvantages remain the same as the single Slot Type Drive.[[br]]

Step 41: Crossed Hi-Torque

[[br]]Perpendicular Hi-Torque recess is milled into the fastener head and has a proven record of performance wherever maximum torque is required. The system is suited in maintenance efficiency where repeated installation and removal of high strength fasteners are encountered. The cup shaped slots serve to help the driver to auto-center, which results in timesaving and extra convenience. I&aposve seen it used on pump head plugs.[[br]]

Step 42: Lotus Head

[[br]]The Shuenn Chang Fa Enterprise Co of Taiwan, possibly also other companies, make this unique cross-slot drive head type.

Fellow Instructable contributor ironsmiter further explains: The Lotus Head Drive is basically a standard cross-slot screw, as it looks the slots are produced by a "much cheaper process". Basically, the screw head is split by a chisel type tool.

The theory is that, by not removing any material, the head retains the full material strength. This is a similar theory as to how a hole that was been punched and drifted, by a blacksmith, is stronger than one that has been drilled out. The Lotus head can also be formed by a machine that costs significantly less to buy and to operate than a recessed head.

The use for these screws is mainly for machine assembly. The constant pressure of the machine driver spindle prevents "skipping" of the bit (that would cause a stripped head, if using hand tools to drive the screw). There is a slightly modified Phillips bit that is used to drive them. It has a matching taper and flat bottom.

As ironsmiter also noted, the example shown is a "quickthread" allowing it to be driven at twice the depth per turn, as compared to a normal screw. It is also a self-drilling model. Primarily designed for use in plastics. You will find similar threads holding almost any cheap plastic radio, light fixture, toy, together. These are all "improvements" to speed up manufacture, and use of the screw. How successful it is at that, I do not know. Just hope you never have to remove one of these. Trying to get a standard Phillips bit, even if you modify it for the flat bottom profile, to grip on these screws is a Royal Pain (frowning) See end-load in Glossary.

According to LennyNero also of Instructables: This style of head is not designed for driving but to be encased in an injection molded plastic or die cast metal part. The odd head shape promotes good grip into the casting and prevents the screw portion from pulling away. He sees these a lot on the stud portions of multi post terminal strips.[[br]]

Step 43: Mission™ SC103 Square Bolt

[[br]]These are used on Mission™ brand Inline Hockey Skates CSD103 and possibly others. There are special tools for these bolts but any standard wrench or pliers can be used with success.[[br]]

Step 44: Parallellogram Head

[[br]]Produced by Jiangyin Ruyi Standard Component Co., Ltd; China. Quite often the application for Parallelogram Head bolts are used as blind fastening, where the head is inserted then crossed within a channel or slot and then fastened with a nut. Regular plier type tools will work well with these heads.[[br]]

Step 45: Robertson�ss

[[br]]In 1908, square drive screws were invented by Canadian Peter L. Robertson. Twenty-eight years before Henry Phillips patented his Phillips head screws. The Robertson screw is considered the "first recess-drive type fastener practical for production usage." The design became a North American standard.

Henry Ford used Robertson screws in the Model A car made by the Ford Motor Company (one of Robertson's first customers). The Model T used over seven hundred Robertson screws. Ford dropped these screws when Robertson refused to give him exclusive rights to its use. Robertson also refused to license other fastener manufacturers, so the design spread very slowly. Many recreational vehicles built in the 1950s use these screws. In Canada, most wood and electrical screws have Robertson recess heads.

A near square recess drive allowed the screw to be placed on the driver prior to the screw being placed in position, so for the first time ever you could start a screw overhead or in a tight spot without an extra hand holding the screw onto the driver. A Robertson head on a screw is much better than a slot head because the screwdriver has great resistance to camout of the screw's head during installation and 4 possible positions to insert the driver. Instructables member roboguy points out that the Robertson design utilizes a "Morse-like" taper so the screw will stick to the bit even when held straight down. This taper allows the tool bit to insert deeper into the recess for more contact surface and thus less camout. To avoid problems make sure both screw and driver are of the matching type as there are many square drive drivers and screws around today that are not Robertson. See Square Drive (next topic). Robertson screwdrivers are available in 6 standard tip-sizes, none metric. Orange and orange are seldom used. The largest black is quite rare. Each identified usually by the handle color rather than by number.

Thanks Brian J. Cooley, Robertson Inc., Tools Division Product Line Manager for North America, for adding information on the 6th Robertson size and for pointing out ALL true Robertson Inc. power bits and insert bits are of the 2 piece variety, they have never produced one piece bits. (I've changed the reference picture as the original one was not not a true Robertson). An easy way for consumers to tell if any fasteners came from Robertson Inc. They use the Robertson ® products manufactured.

#00: orange - used with #1-2 Screws
#0: yellow - used with #3-4 Screws
#1: green - used with #5-7 Screws
#2: red - used with #8-10 Screws
#3: black - used with #12-14 Screws
#4: black - used with #16+ Screws


Step 46: Square Recess

[[br]]Only Robertson Inc. makes Robertson® screws and drivers, the others are generically called Square Drive and are made by several manufacturers and brands since the patents have expired on the Robertson. The Square Drive head is an American clone of the Canadian Robertson® that has a square recess but not tapered and has very sharp corners. Likely this difference was to avoid patent infringements. The patented Robertson® driver has a slight taper, and slightly rounded corners. See Robertson® Recess.

Two methods of fabrication are the machined one piece and the two-piece is a forged steel tip press fitted into a regular steel tip holder part. Several companies each with their own select brand name produce square Drive.

Due to the lack of taper, the hole must be oversize relative to the screwdriver, and is much more likely to camout than the Robertson®. It is infuriating that Home Depot® and the tool companies like Bosch® and Dewalt® bring square drive bits into Canada that almost fit Robertson® screws and are marketed as equal and are unmarked. For any Canadian readers that want bits that work, try to buy the bits that are color-coded red, green, black as well check the engraving is an R on the bit. Don&apost trust the cheaper bulk packs. Never trust a Robertson that says "Made in America"; it is likely a Square Drive. A "fresh" American Square drive driver with a "real" Robertson® screw head sticks so tightly that it can take a significant yank to get them disengaged. This is advertised as a selling point of the American Square drivers here in Canada. Unfortunately, if you have to pop out the driver, it usually means you&aposre damaging the tool and is more difficult to use from then on. Real Robertson® drivers do not suffer from this with Robertson® screws. So, while they don't stick quite so tightly, the drivers really do last a long time, and they're just as good at keeping grip under power. Bit sizes come in only four sizes and application and are rarely color-coded.[[br]]

Step 47: Tamperproof Square Recess

[[br]]Basically a square recess, but the recess also has a temperproof center pin. The drive must have the mating hole in the center end.[[br]]

Step 48: Scrulox® Recess

[[br]]This is a Robertson Inc. version of a Square Drive. See Robertson Recess and Square Recess. After all fair is fair. [[br]]

Step 49: Phillips® Recess

br]]This cross drive screw story starts when Henry Phillips purchased a crude form of a cruciform-recessed screw head concept from an Oregon inventor named J.P. Thompson.

Henry F. Phillips (1890 to 1958), a U.S. businessman from Portland, Oregon, has the honor of having the Phillips head screw and screwdriver named after him.

Phillips developed Thompsons" invention screw into a workable form. Phillips had come up with a recessed cross screw designed for efficiency on an auto assembly line. The idea was that the screwdriver would turn the screw with increasing force until the tip of the driver popped out, called camout. When tightening a Phillips screw with a Phillips screwdriver you will notice that when the torque gets to be too strong, the screwdriver winds itself out of the screw so the screw head would not be ruined or brake off.

Phillips also founded the Phillips Screw Company in Oregon in 1933, but never actually made screws. He had called on every established screw manufacturer in the US and was told simply that the screw could not be made. Screw makers of the 1930s dismissed the Phillips concept since it calls for a relatively complex recessed socket shape in the head of the screw; as distinct from the simple milled slot of a slotted type screw.

Phillips then called on the American Screw Company, a newcomer to the industry whose new president, Eugene Clark, personally became interested in the new product, despite the opposition of his engineers, who like others in the industry had insisted it could not be made. According to one printed report, the president of American Screw Company said: "I finally told my head men that I would put on pension all who insisted it could not be done. After that an efficient method was evolved to manufacture the fasteners and now we have licensed all other major companies to use it."

Use of the Phillips screws spread through the automobile industry at a rapid rate. By 1939 it was used by all but two automobile manufacturers. By 1940, Phillips" screws were used by the entire automotive industry, although one major manufacturer still would not use them on its passenger cars. Gradually the Phillips screw and screwdriver worked their way into other industrial applications; then consumer products, and eventually showed up in hardware stores.

The American Screw Company spent approximately $500,000 in the 1930s to produce the Phillips screw and obtained patents on the manufacturing methods. It was the sole licenser of the process. By 1940 10 American and 10 foreign companies were licensed to manufacture the screw. Although Henry Phillips received patents for the drive design in 1936 (US Patent #2,046,343, US Patents #2,046,837 to 2,046,840), it was so widely copied that by 1949 Phillips lost his patent ("exclusive" protection would only have lasted until 1956 anyway.)

Phillips' major contribution was in driving the crosshead concept forward to the point where it was adopted by screwmakers and many automobile companies. Henry Phillips died in 1958 at the age of sixty-eight.

The Phillips system was invented for use in assembling aluminum aircraft, with the object of preventing assemblers from tightening screws so tightly that the aluminum threads strip. The driver will cam out before that happens. The Phillips screwdriver has four simple slots cut out of it, each slot is the result of two machining processes at right angles. The result of this process is that the arms of the cross are tapered and has slightly rounded corners in the tool recess. Phillips is designed so that when excess torque is applied it will cam-out rather than ream the recess or destroy the bit. The driver has a 57° point with a blunt tip, tapered wings. Identified in ANSI standards as type I.

In all cross drive systems the driver will self-align with the fastener. The tapered design that allows camout can become a problem as the tooling that forges the recess in the head of the screws begins to show signs of wear. The recess becomes more and more shallow, which means the driver will bottom-out too soon and will cause the driver to cam-out early. Another problem is even though the ease to insert, Phillips screws can be tough to get back out. The main disadvantage is the screwdriver pops out too readily, stripping the screw, gouging the work, and in general transferring all the problems that were formerly with the Slot design. Consumers are likely to think that any screw head with a cross drive recess is a Phillips which can lead to other problems.[[br]]

Step 50: Tamper Pin Phillips® Head

[[br]]The Tamperproof Screw Company was founded in the late 1970&aposs when George Friedman developed the Phillips® security screw. As its name states it has an internal pin within the Phillips recess of the head, requiring a special insert bit or key wrench to insert and remove. This unique feature renders the Tamper Pin Phillips® Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. The Philips/Cross tamperproof profile has the same properties as the classic Philips/Cross; the difference is that the tool has a hole located in the tip and the screw head has a small central pin.

Theft Proof fasteners are virtually impossible to remove without the matching driver. These screws are easy to drive & remove with matching tool, but cannot be removed with Phillips® driv�ue to the design of the Tamper Pin Phillips® Security Screw it is suitable for higher torque applications and is "2 way". Available in sizes #1, 2, 3.

Step 51: ACR® Phillips®

[[br]]Patented by the Phillips Screw Company to compliment the Phillips® drive. ACR® was developed for the aerospace industry to avoid costly head stripping and to assure easy insertion and removal of screws during assembly and maintenance. The advanced ACR® Phillips® system keeps the driver securely mated to the screw during fastener removal eliminating damaged screw heads and drives while preventing damage to costly panels, avionics and structures. The ribbed mating surfaces of the driver and screw head lock together providing greater maintainability. There are 3 types of the drive bit but the most common is for removal and driving.

Maintainers prefer the ACR® Phillips® system because they do not have to push hard on the driver, reducing fatigue and the risk of injury. The results are securely removed screws every time with lowered cost, more productive workers, fewer drill outs, and fewer problems to fix in overhaul. ACR® Phillips® screws are also compatible with common Phillips® drivers allowing emergency modifications and repairs.[[br]]

Step 52: Phillips Square Driv®

[[br]]A combination drive designed by marrying the classic Phillips® cruciform recess and the popular square drive recess. The result is a highly efficient and functional multi-driver servicable recess.

This drive system has an increased driver bit cross-section significantly increases the longevity of the driver bit, reducing overall tool costs. Combines positive characteristics of both the Phillips® and the Square Drive with few negative characteristics. Not as prone to camout; higher torques than either original drive. Screw damage is minimized and drive tool life is extended. In addition, there is a consistent stick between the driver and the screw, making hard to reach joints a simple task.[[br]]

Step 53: ACR® Phillips Square Driv®

[[br]]Also from the Phillips Screw Company and very similar a Phillips Square-Driv® plus the added ACR® Anti-Camout Ribs. It has all the advantages of the Phillips Square-Driv®. ACR® is for reduced camout, reliable stick-on and high torque. The screw heads are marked with double ticks as shown.[[br]]

Step 54: Phillips Square Drive 2®

[[br]]Also by Phillips Screw Company. Yet another combination drive system. Not much information on the Internet about this drive. It could mean the head and drive is just not common yet or that the artists version of the screw head pattern is incorrect. I question the thin tick lines. Except for the identification on the bit, could this really just be Phillips II®?[[br]]

Step 55: Phillips II®

[[br]]A recent evolution of the Phillips® design resulted in a next generation, patented Phillips II®. The ACR® improvement is basically a Phillips® screwdriver that has ACR® ribs, making it ideal for assembly line and home use. Phillips II® screws have ribs in the recess of the screw. The ribs mate with the ribs found on the Platinum tipped Phillips II® ACR® driver bit. This rib-to-rib connection allows for driving in and backing out the screw. The ribs are on either or both the driving and removal faces on the wings. The patented anti camout ribs (ACR®) guarantee stick fit, easier drive and less fatigue. Deck Mate™ screws are a good example of these and the Deck Mate™ driver bit often comes with the screws. Screw heads are marked with double hash marks 45° to cross recess.

The rib-to-rib connection allows for more torque, off-angle driving, heads that will not snap off, and screws that will not strip. You will never have another stripped screw that cannot be removed! You can not drive a square drive or a star drive off angle! Proprietary threads means faster drive. Patented anti-camout ribs (ACR®), guarantee stick fit, easier drive and less fatigue. Deck Mate™ screws can be driven with #2 Phillips® or #2 Square Driver bits but for best performance use Deck Mate™ driver bits with ACR®. You will never have a stripped screw that cannot be removed.

sgk07072000 says:
Deck Mate is owned by Home Depot and they have changed manufacturers so they no longer use this bit.  The manufacturers website: http://www.deckmatescrews.com/   These can now be purchased at Lows under the Phillips II Plus label.

Step 56: Quadrex®

[[br]]Founded in 1978, AVA Specialty Fasteners Ltd. of Canada presents Quadrex® which combines the best features of Cross Recess and Square Socket drives. The Quadrex® recess increases productivity by incorporating the superior torque transmission and cling fit of the Square Socket drive with the desirable field repair and retrofitting features of the Phillips® drive.

This controlled radius recess has been designed for optimum driver engagement while providing clearance for wear and plating buildup. Added features include: Universal Application, Increased Productivity, Reduced Inventories, Assembly Line Economics and Universal Acceptance.[[br]]

Step 57: Recex Recess

[[br]]The Idea of the Robertson/Phillips (Recex) combo drive was invented by Robertson Inc. in Milton Ontario and Recex® is the only combo drive Robertson Inc. endorses. The patented Recex Combo Recess drive insures you always have the correct driver bit to install or adjust your finished wood working project.

Information by Brian J. Cooley, Robertson Inc., Tools Division Product Line Manager for North America.

Step 58: Frearson or Reed & Prince

[[br]]A later cross drive system referred to in ANSI standards as Type 2 recess. It was developed by an English inventor named Frearson and was produced from the late 1930&aposs to the mid 1970&aposs by the former Reed & Prince Manufacturing Company of Worcester, Massachusetts (was liquidated in 1990 with the sale of company assets).

Today it is mostly referred to as Frearson but occasionally still by its former name of Reed & Prince. This drive is very similar to a Phillips but has a more pointed 75° V-shape. It is found mainly in marine hardware. The tool recess is a perfect cross, unlike the Phillips head, which is designed to camout.

Its advantage over the Phillips drive is that one Frearson driver or bit fits all Frearson screw sizes, although there are 2 sizes available. Advantages include improved torque with minimal camout. Unfortunately the screw head recess appears to be a Phillips and so it is too easy to use the wrong tool or screw.

Instructables member whit3rd adds: The Reed & Prince tip isn't blunted, so won't fit 'normally' in a Philips #1, #2, or #3 screw; anyone who pays attention to the feel of the screwdriver will not mistake it for a Philips. [[br]]

Step 59: JIS Japanese Industrial Standard

These are often improperly referred to as Japanese Phillips. Commonly found in Japanese equipment. JIS looks much like a Phillips screw (and even more similar to Frearson), but is designed not to camout and will, therefore, be damaged by a Phillips screwdriver if it is too tight. Heads are usually identifiable by a single dot "dimple" to one side of the cross slot. JIS B 1012:1985 screw standard is used throughout the Asia market and Japanese imports. The driver has a 57° point with a flat tip and parallel wings.

Many people and companies outside of the Asian market have no idea what JIS is/are. With the similarity in appearance to the Frearson and the Phillips the screws are often damaged in removing and installing with the wrong tools. The JIS driver can be used on Phillips quite easily but not reciprocally. Drivers are not easily available in North America; try your local Radio Controlled Airplane hobby shop. Most RC Helicopters use JIS screws to mount the propellers.

Fellow instructable members gentry & Joe Katz: talk about the early Japanese motorbikes, as in the 1950's and 60's, the first Japanese motorbikes that came into the US were so frustrating to work on. The case screws looked like Phillips but all a Phillips driver did was strip out the recess. Both talk about needing to use vice-grips and even impact drivers - 'cause an impact would get 'em out even if the bit didn't fit well.

Eiko ISO Screw

Fellow instructable contributor Gecik says: In the 1970's and early 80's -- back when "movies" were strips of photographic film I repaired those movie projectors. Eiki was a Japanese company with very good, easily maintained 16mm projectors used extensively at colleges and universities (at least in the USA). Eiki projectors used what they called "ISO screws" and which sound very much like your JIS description. The ISO screws were difficult to remove with a Philips screwdriver, but were a breeze with the ISO screwdrivers supplied by Eiki. These screwdrivers also worked well with Philips. I had to purchase ISO screwdrivers through Eiki; a company in Kobe, Japan manufactured the tools. After the big earthquake in Kobe, the manufacturing company did not rebuild. The present-day Eiki has no historical knowledge of the ISO screwdrivers or that they had even used these screws. The "ISO screw" that I remember -- and still see in VCRs (soon-to-be-extinct also) and other Japanese manufactured goods has what I would describe as a "dimple" or a depression/dot between two sides of the "X."

I'm almost sure what Gecik refers to, as Eiki ISO screws were actually JIS-Type screws with ISO metric threads. Two ways of saying the same thing. Similar to if I'd call them Yuyama ISO screws.

You see my own JIS experience is with a medication-dispensing machine made by Yuyama of Osaka Japan. During the service training on these units along came JIS as they called it. Each screw has an identifying "dimple" on the head which I take to understand indicates that the cross-point head is not a Phillips. The screws are also all metric.

Step 60: Sel-O-Fit®

[[br]]Sel-O-Fit® is a registered trademark of Cooper Industries. The bits are designed to provide a more efficient means of driving Pozidriv® screws. The driver has a 46° point with a flat tip, parallel wings.

The Sel-O-Fit® bit places torque on the strongest and most mechanically advantageous portion of the driver tip. This allows more torque to be applied while minimizing the possibility of breakage and camout.[[br]]

Step 61: BNAE or French Recess

[[br]]Also called BNAE NFL22-070 after its Bureau de Normalisation de l'Aeronautique et de l'Espace standard number. Possibly a security screw drive system. Easily confused with a JIS or Frearson recess screw but with driver blades are modified into two step diameters.[[br]]

Step 62: Mortorq® Super

[[br]]The Mortorq® Spiral Drive recess developed by Phillips®, is much shallower than other standard recesses on the market, and can be put into a much shallower head without affecting the strength of the screw. This assembly allows for a shallower counterbore, reducing material thickness without compromising the joint strength, because it does not affect the material thickness below the counterbore. A Mortorq® recess uses full wing contact with driver bit in both drive and removal directions.

Aerospace designers have had to compromise on fastener performance. Previously, shallow head styles had poor torque transfer and damaged easily while robust drives required thicker material and added weight. The unique shape provides full contact of the driver over the entire recess wing resulting in extremely high torque capability without the risk of damage. Depth of the recess in the fastener head is minimized resulting in true high performance in 100° flush head and shear head applications. The open recess concept allows driver to recess misalignment and compensates for paint build-up without degrading torque performance. Workers can easily install and remove panel and structure fasteners at odd angles without high muscle stress or fear of damage to surrounding surfaces. Larger driver cross-sections and curved surfaces provide extended tool life and resistance to tensile fatigue fracture when used with high load pulse tools.[[br]]

Step 63: Torq-Set®

[[br]]The Torq-Set® offset cruciform fastener system, by Alcoa Fastening Systems, is a proven product in the aerospace market. For applications where screws or bolts must be torque-tight, Torq-Set® meets the requirements and beats the competition. One look at the innovative recess design of Torq-Set® tells the story. Its offset cruciform configuration takes the sure-fitting dependability of the original Phillips design one step further toward an ultimate torque driving system. Torq-Set® ensures a torque tightness that satisfies the rigorous demands of todays aerospace applications.[[br]]

Step 64: Torq-Set® ACR®

[[br]]Torq-Set® ACR® ribbed offset cruciform drive has become the revolutionary fastener system preferred by aeronautical engineers for use on military and commercial aircraft, missiles, satellites, and weapons systems worldwide.

A single driver inserts and removes the fasteners. The interlocking ribs - applied to the removal side of the driver bit and screw surfaces - eases fastener removal, even after a threaded fastener has become corroded, seized, or frozen. Camout is never a problem when driving in either direction with the ACR® system. When meeting demands of high torque applications, the Torq-Set® ACR® drive system delivers ultimate performance while protecting against camout. The offset cruciform shape with interlocking ribs of the Torq-Set® ACR® design is unmatched for sure steady driving. Additionally, all Torq-Set® ACR® driver bits and recesses are interchangeable with standard Torq-Set ® components, thereby eliminating potential difficulties during emergency field maintenance. Available in sizes #0, 1, 2, 3, 4, 5, 6, 8, 10.[[br]]

Step 65: Sentinel® Security Screws

[[br]]The Sentinel® Security Screw has a unique head that requires only a standard 'Pozi' screwdriver for insertion.

There is no surface to catch for counterclockwise force. This unique feature renders the Sentinel® Security Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Due to the design of the Sentinel® Security Screw it is suitable for higher torque applications and is a 1-way permanent vandal resistant security screw.[[br]]

Step 66: 4-Hole Security Nuts & Bolts

[[br]]The 4-Hole Security Nut is much as its name states, it has 4 location holes in the nut that are surrounded by a slim circular groove, requiring a special tool to tighten or remove the 4-Hole Nut. This unique feature renders the 4-Hole Security Nut tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Due to the design of the 4-Hole Security Nut it is suitable for low to medium torque applications and is 2 way. [[br]]

Step 67: Microtech® 4-Pin

See Microtech® 3-Pin. Pictures used are copywritten by Microtech.

Step 68: 4-Notched

[[br]]These screws were used on some now discontinued mobile phones. No further information found.[[br]]

Step 69: Bristol 4-Spline Drive

[[br]]Developed by the Bristol Co, the multiple spline drive system is recognized by design engineers as the superior method of transmitting torque because nearly 100% of wrenching force is applied at right angles to the load bearing spline surfaces of the socket. Other drive systems dissipate a significant amount of force into radial thrust, tending to expand the socket rather than tighten the screw. The substantial and effective wrench engagement inherent in the Bristol design addresses the problems caused by other fastening systems such as cam-out, socket reaming and rounding" of wrenches.

Bristol Spline Drive suggested applications include set screws and smaller cap screws requiring severe tightening, and for screws with shallow sockets. For frequent removal and resetting of screws and plugs, such as for tool inserts, purge screws, drain/filler plugs, template retainers, and replacement of worn parts. In applications requiring softer screws such as stainless steel or non-ferrous materials.

Decades ago, Bristol engineers invented the Bristol Spline Drive System for use in electromechanical instruments. They required screws and wrenches that could stand up to industrial environments, vibrations, and frequent removal and resetting. Bristol wrenches have been in continuous production in the United States since their original introduction. Usual number of flutes is 6, but some diameters come with 4 flutes. Sized in inches:
0.048, 0.060, 0.069 (4 flute), 0.072, 0.076 (4 flute), 0.096, 0.111, 0.145, 0.183.[[br]]

Step 70: Torx-Plus® Security

[[br]]The Torx-Plus® Security Screw is an upgrade from its predecessor (6-Lobe TX Security Screw) providing a higher degree of security as the design is patented and the driver bits are limited to Torx-Plus® distributors. The vandal resistant Torx-Plus® Security Screw has a unique 5-Lobe Torx head that requires a special driver bit for insertion, which is registered to restrict and control availability. This unique feature renders the TorxPlus® Security Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws.

Manufacturers the world over are discovering how the Torx® Drive increases torque transfer, extends tool life, and increases productivity on their assembly lines. Features include a non-symmetrical, elliptically-based geometric configuration; five lobes with solid post in center of recess; concentricity and tight tolerances of special tools make them very difficult to counterfeit.

Currently, Torx-Plus® heads and drivers are patented, slowing adoption in the marketplace, but is licensed to a number of tool manufacturers including Camcar and Facom. The control for these licenses are held by Textron.[[br]]

Step 71: External Torx-Plus® Low-Profile 5-Lobe

[[br]]Textron Fastening Systems is now Acumet Global Technologies and developed the External Torx-Plus® Low-Profile screw drive system.

The external hex drive allows high torque transmission, but can fail quickly due to weaknesses inherent in its design. External Torx-Plus® low-profile head drive system is engineered to provide optimal torque transfer and extended tool life, with a head height similar to hex or pan head fasteners. The drive utilizes a 0° angle. Lobe engagement spreads forces over large area to prevent stress risers that cause tool and fastener damage. Higher torque transfer capability than corresponding internal recesses. Drive system strength 5 to 6 times greater than normal seating torque. Excellent high-torque drive system for miniature fasteners

An external Torx® version exists, where the screw head has the shape of a Torx® screwdriver bit, and a special Torx® socket is used to drive it. These are found primarily on automobile engines. [[br]]

Step 72: Cinstar® Security

[[br]]The Cinstar® Security Screw is an upgrade from its predecessor (6-Lobe TX Security Screw) providing a higher degree of security as the design is patented and the driver bits are limited to Cinstar® distributors. The vandal resistant Cinstar® Security Screw has a unique 5-Lobe Torx® drive that requires a special driver bit for insertion, which is registered to restrict and control availability. This unique feature renders the Cinstar® Security Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Tamper proof & Re-usable Security Fixing

Step 73: Penta® Drive

[[br]]Penta® shapes are extremely difficult to make, and Bryce Fasteners keeps the dimensions secret. They have been tested under very severe security demands and have a stellar track record. The Penta® Nut has Patent security.[[br]]

Step 74: Penta-Head™ Bolt

[[br]]A product of Bryce Fastener. The Penta-Head" Bolt is available when a traditional tamperproof screw just will not do. These pentagon shaped heads prevent a traditional socket or wrench from removing them. They are offered in 3/8-16 and 1/2-13 sizes up to 3.5" long.[[br]]

Step 75: Penta Nut™

[[br]]A product of Bryce Fastener. Pentagon shapes are extremely difficult to make, dimensions are secret. They have been tested under very severe security demands and have a stellar track record. The Penta Nut™ has Patent security.

Oversized Penta Security Nut sizes are available in sizes from 5/16" (M8) to 7/8" (M16). All nuts feature compression rings for binding & sealing, recess that provides high torque, deep sockets for overrun of bolts, cone shape to repel vice grips & are manufactured out of 316 stainless steel stock.[[br]]

Step 76: Penta-Plus™

[[br]]The geometry of Penta-Plus™ makes it more secure than all other tamper proof screws. Penta-Plus™ is proprietary to Bryce Fastener and configured to keep Torx-pin and Hex-pin tamper-resistant bits out. Other tamperproof screws have bit tips sold on the open market. Penta-Plus™ is sold only by Bryce Fastener to maintain its integrity as a high security tamper-proof screw. Penta-Plus™ has been proven to be tamper-resistant and vandal-proof in some of the most extreme situations (securing laptop computers in open kiosks) without failure. Next to the Keyed-Lok™ security lock, this is the most tamper proof screw on the market.

Center pin is oversized. Configured to keep Torx® hex-pin bits out. Bit tips are tight fitting, allowing more torque than almost all other tamper-proof screws. The Penta-Plus™ screw and drivers are controlled. The bit tips are only sold to the user of the screws. The pentagram geometry is extremely secure and difficult to make.[[br]]

Step 77: Penta-Plus® Tamperproof

[[br]]An advanced, more secure version of Penta-Plus®. Bryce Fastener retails exclusive rights and control over the restricted screws and drive, making these very secure from tamper and vandal.[[br]]

Step 78: Uni-Screw® Security

[[br]]Very similar to the Uni-Screw® but with enhanced security feature of custom off rotation of each pentagram rather than in-line hex. Close tolerance pentagrams are very difficult to tamper or vandelize.[[br]]

Step 79: Kinmar® Removable Two Way Security Nut & Screws

[[br]]Another unique high torque security drive system which can only be undone with the unique matching socket. This product is extra resilient to attack because of its rounded shape and case hardened steel construction. Removable so it is a "2-way" screw. Requires matching tooling. Available in sizes M5 to M12.[[br]]

Step 80: Hexagonal Recess Head, Unbraco® or Allen Key

[[br]]Probably the most common of all fastener heads, hex heads are also very old. Fasteners with hexagonal heads were used to hold armor together in the fifteenth century.

The Unbrako® fastener brand name is widely recognized throughout the world. Unbrako® socket screws are used in machine tools, tools and dies, earth moving and mining machinery, and a wide range of industrial and engineering applications.

To find the size of wrench needed to turn a hex head recess, measure from flat to flat. Common smaller hex sizes include -
Inch sizes:
0.050", 1 / 16 ", 5 / 64 ", 3 / 32 ", 7 / 64 ", 1 / 8 ", 9 / 64 ", 5 / 32 ", 3 / 16 ", 7 / 32 ", 1 / 4 ", 5 / 16 ", 3 / 8 "; Metric sizes:
1.27 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, and 6 mm. [[br]]

Step 81: Tamper Proof Hex-Pin™ Drive

[[br]]From Bryce Fasteners, the Hex-Pin™ Security Screw as its name states has an internal pin within the hexagonal socket of the head, requiring a special insert bit or key wrench to insert and remove. This unique feature renders the Hex-Pin™ Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Due to the design of the Hex-Pin™. Security Screw it is suitable for medium torque applications and is "2 way". TR-HEX: 5/64, 3/32, 7/64, 1/8, 9/64, 5/32[[br]]

Step 82: External Hex Drive

[[br]]What more can be said for the common hex head bolt or nut, they are everywhere. Corners tend to round when over torqued especially with an open-end wrench. The advantage over a square shaped head is the multiple ways the wrench will fit, especially useful in close applications with limited tool access. The disadvantage is that in high torque applications, loose tools or repeated use the corners tend to round out. They come in both metric and non-metric sizes and in many single wrench or socket driver styles.[[br]]

Step 83: Bristol 6-Spline Drive

[[br]]Developed by the Bristol Co, the multi-spline drive system is recognized by design engineers as the superior method of transmitting torque because nearly 100% of wrenching force is applied at right angles to the load bearing spline surfaces of the socket. Other drive systems dissipate a significant amount of force into radial thrust, tending to expand the socket rather than tighten the screw. The substantial and effective wrench engagement inherent in the Bristol design addresses the problems caused by other fastening systems such as camout, socket reaming and rounding" of wrenches.

Decades ago, Bristol engineers invented the Bristol Spline Drive System for use in electromechanical instruments. They required screws and wrenches that could stand up to industrial environments, vibrations, and frequent removal and resetting. Excellent for set-screws and smaller cap screws requiring severe tightening, and for screws with shallow sockets. For frequent removal and resetting of screws and plugs, such as for tool inserts, purge screws, drain/filler plugs, template retainers, and replacement of worn parts. Bristol wrenches have been in continuous production in the United States since their original introduction. Thanks fellow Instructable member fernblatt for assistance on these. Usual number of flutes is 6, but some diameters come with 4 flutes. Bristol spline drivers are available from Xcelite/Cooper and are SAE-sized (non-metric). Sized in inches:
0.048, 0.060, 0.069 (4 flute), 0.072, 0.076 (4 flute), 0.096, 0.111, 0.145, 0.183[[br]]

Step 84: Torx® Drive

Torx® was developed in 1965 by Camcar Technical center, located in Rockford, Illinois, of Acument Global Technologies (formerly Camcar Textron), is the trademark for a type of screw head characterized by a 6-point star-shaped recess. People unfamiliar with the trademark generally use the term star, as in star screwdriver or star bits. The generic name is hexalobular internal driving feature and is standardized by the International Organization for Standardization as ISO 10664.

Torx® screws are commonly found on automobiles, hard disk drives, computer systems (Compaq® uses almost exclusively T15 screws) and consumer electronics, but are also becoming increasingly popular in construction.

This style of head is now very common in trucks and automobiles. The walls of the recess are not tapered. Drivers greatly outlast similar hex head drivers.

Torx® head sizes are described using the capital letter "T", followed by a number. A smaller number corresponds to a smaller point-to-point dimension of the screw head. Common sizes include T10, T15 and T25, although they reach as high as T100. Only the proper driver can drive a specific head size without risk of ruining the driver or screw. The same series of Torx drivers is used to drive SAE, metric and other thread system fasteners, reducing the number of bit sizes required. Excellent sizing charts available on the Wiha Toolswebsite.

Fellow instructables contributor peter_broach adds: CNC machines often use rotary broaching tools to make forms like these in custom screws.

Step 85: E-Torx® (External)

An external E-Torx® version exists, where the screw head has the shape of a Torx® screwdriver bit, and a special Torx® socket is used to drive it. These are found primarily on automobile engines. These drive screws and bits are available in both 5 and 6 lobe designs. E-Torx® head sizes are described using the capital letter "E", followed by a number. A smaller number corresponds to a smaller point-to-point dimension of the screw head. Excellent sizing charts available on the Wiha Tools website.

Step 86: Torx Plus® Drive

Camcar LLC developed an improved profile of Torx® designated Torx Plus®. The improved lobe design allows for increased torque transmission and virtually eliminates camout. By reducing camout tool slippage and screw damage is reduced, which extends tool life and reduces user fatigue. Currently, Torx Plus® heads and drivers are patented, slowing adoption in the marketplace, but is licensed to a number of tool manufacturers including Camcar and Facom. Textron holds the specifications for these licenses. Standard Torx® drivers can be used to drive Torx Plus® screws, but Torx Plus® drivers will not fit standard Torx® screws. Torx Plus® head sizes are described using the capital letters "IP", followed by a number. A smaller number corresponds to a smaller point-to-point dimension of the screw head. Excellent sizing charts available on the Wiha Tools website.

Step 87: Torx Plus® External Low Profile Drive

[[br]]Camcar also developed the Torx Plus® External low profile drive. This drive system is engineered to provide optimal torque transfer and extended tool life, with a head height similar to hex or pan head fasteners. They utilize a hex flange head or pan head bearing surface with 0° angle. Lobe engagement spreads forces over large area to prevent stress risers that cause tool and fastener damage. Higher torque transfer capability than corresponding internal recesses. This provides a drive system with strength 5 to 6 times greater than normal seating torque. Lower head volume (weight) than hex and pan head fasteners (18% and 41% respectively)

Fastener Sizes - from H7EP (#0000, M0.6) through 42EP (1", M24). Note: Special sockets are required.[[br]]

Step 88: Tamper Pin TX Security Screws

[[br]]Torx® is a registered trademark of Acument Intellectual Properties LLC, see Torx® Drive step. Tamper resistant Torx® screws feature a post in the center of the recess. This post will only fit into a tamper resistant Torx® bit. They are also referred to as Torx security drives, Torx security heads, Torx tamper resistant drives, Torx tamper resistant heads, star tamper resistant screw, Torx security drive screw, Torx security screw, Torx security tamper resistant screw

The Tamper Pin TX Security Screw as its name states has an internal pin within the 6-lobe socket (star drive) of the head, requiring a special insert bit or key wrench to insert and remove. This unique feature renders the Tamper Pin TX Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Due to the design of the Tamper Pin TX Security Screw it is suitable for higher torque applications and is "2 way".

Except for the pin, the Tamperproof Torx® heads are the same as the internal recess heads, with sizes including - TT-7, TT-8, TT-9, TT-10, TT-15, TT-20, TT-25, TT-27, TT-30.[[br]]

Step 89: TTAP®

[[br]]TTAP® is an improved "hexalobular" drive from Infast AS Oslo, Norway, designed for no wobbling and stable stick-fit. The stick-fit no wobbling feature enables one-handed operations without magnetic holder. TTAP® makes collated screw feeders work efficiently. TTAP® is backward convertible with generic hexalobular drive. TTAP® is an innovative new hex-lobe drive system with distinct advantages over the generic hex-lob (Torx®) and is backwards convertible, meaning standard Torx® drivers can be used to drive TTAP® screws, but TTAP® drivers will not fit standard Torx® screws. No need to push as there is no end-load. With stick-fit, no magnetic bit holder needed and thus there are no steel splinters to clog the bit.

Currently, TTAP® heads and drivers are patented, slowing adoption in the marketplace. Information hints there is also a tamper resistant version of TTAP® but found no information yet.[[br]]

Step 90: Polydrive®

[[br]]Polydrive®, also known as Ribe CV", Ribe CS" or simply Ribe", is a fastener specification used primarily in the automotive industry, for example the VW engine head bolts. Ribe CV" for spline socket head screws are a registered TM of Richard Bergen GmbH Co.

A Polydrive® bit has 6 teeth at equal spacing and with flat tips to the teeth. Size is determined by OD diameter at the star points. Functionally, it is similar to Torx® and Bristol Spline drive, all of which are systems using internal bit-socket drivers along with specially-designed bolts, screws, and other fasteners. Its primary advantage over older fastener driver standards, such as the common Phillips® head (and its sibling Pozidriv®), is that it resists camout, and is thus used in higher torque applications such as brakes and drive-shafts.[[br]]

Step 91: 6-Lobe Screw Drives

[[br]]After the expiration of the Torx® design patent in 1988, many non-licensed fastener manufacturers started producing screws with what has become known as the 6-Lobe recess. Today only those companies who are licensed by CAMCAR-Textron can market this design as a Torx® Recess because even though the patent has expired the trademark is still active. Those who are not licensed by CAMCAR-Textron but use the Torx® name are in violation of international trademark laws. See referenced article by Joe Greenslade in references at the end of this project.[[br]]

Step 92: Tam-6-Lobe™

[[br]]A tamperproof, Torx-like, 6-lobe screw drive system product with tamper proof center pin by Bryce Fastener.[[br]]

Step 93: Tamperproof System Zero® Security

[[br]]System Zero® was the registered trademark of Deltight Industries Ltd., but Deltight has been taken over by BAS Components Ltd. and these screws are now a proprietary product manufactured in Sevenoaks Kent, UK.

The System Zero® Security Screw has an external non-slip drive head, requiring a special tool to insert and remove. This unique feature renders the System Zero® Screw tamper proof, reducing the risk of vandals or intruders tampering or undoing the screws. Due to the design of the System Zero® Security Screw it is suitable for higher torque applications and is "2 way", also with the non slip external drive damage to adjacent components is avoided.

The unique head-style requires a dedicated driver for installation and subsequent, authorized removal. In combination with the driver the head design gives high torque transmission, which in turn generates high clamp loads. Virtually 100% secure without associated removal tool. Sizes from M3 to M8 machine and No.2 to No.14 self tapping. They have uses in beekeeping and are especially easy to apply. [[br]]

Step 94: Seton Security Screw Kit

[[br]]Seton Security of the UK, sells a Screw Kits (Unknown manufacturer) that comprises: 4 x Stainless Steel Security Screws, 4 x Plugs and 1 Hex Drive Security Bit (1/4" ratchet or driver required). Appears to be a double-triangle design with tamper center pin. Once fastened the screws cannot be undone with a conventional screwdriver.[[br]]

Step 95: Uni-Screw®

[[br]]The Uni-Screw® is being manufactured and distributed by Forward Engineering under a license from Uni-Screw® and the first commercial products are aimed at the building and DIY markets. Strong interest has also been shown by several industrial organizations. Uni-Screw® can be a direct replacement for 25 other types of screwdrivers. No need for surplus drivers anymore!

A new design of screw head, the Uni-Screw®, has been developed to rival the well-established slotted, Phillips® and Pozidriv® screws. It is based on a series of hexagonal recesses that avoids camout, which occurs with the other designs when higher torques are applied.

The company website claims Uni-Screw® to be the first driver to drive both imperial and metric fasteners, virtually eliminates camout and stripping, positive control with stick fit, and increased productivity. Other benefits include the need for only one driver over a wide range of screw sizes and easy alignment of driver to screw.

Other recess forms can be used including pentagon and heptagon to provide high tamper resistance, and these can be tailored for a single user to give total security.

Step 96: 7-Node Drive

[[br]]No further information found on this type of drive, may just be artist perception.[[br]]

Step 97: Posidrive®

[[br]]Pozidriv® was jointly patented by the Phillips Screw Company and American Screw Company in the USA. Developed by GKN in the 1960s, the recess is licensed from Trifast PLC in the rest of the world. It is the de facto standard in Europe and most of the Far East, where Phillips® is almost nonexistent. The proper Pozidriv® screws have a flatter bottom to the socket, and steeper sides, so the driver doesn't camout as easily. The name is thought to be an abbreviation of positive drive.

Pozidriv® is similar in appearance to the classic Phillips® crosshead, but in fact is substantially different. On close examination you will notice a second set of cross-blades at the root of the large cross-blades. These added blades are for identification and match the additional makings on the head of Pozidriv® screws, known as "tick" marks, single lines at 45° to the cross recess. So, the marks are for more than identification purpose. Pozidriv® also does not have the rounded corners that the Phillips screw drive has. The tip or the driver is blunt which also helps it to seat better into the recess in the screw, unlike the Phillips® which comes to a sharper point.

Identified in ANSI standards as type IA. Pozidriv® screws can be turned by Phillips® screwdrivers, but Pozidriv® drivers won't turn Phillips® screws, although they should not be used as they tend to ride out of the recess and round the corners of both the tool and screw recess.

The largest advantage it offers is that, when used with the correct tooling in good condition, it does not cam out, allowing great torque to be applied. The chief disadvantage of Pozidriv® screws is that they are visually quite similar to Phillips®, thus many people are unaware of the difference or do not own the correct drivers for them, and use incorrect screwdrivers. This results in difficulty in unscrewing the screw and in damage to the slot, rendering any subsequent use of a correct screwdriver unsatisfactory.[[br]]

Step 98: SupaDrive®

[[br]]Often refered to as Pozidriv®, these two drives are not exactly the same. Each has its own driver but both will also work with the other. The screw head is similar to Pozidriv® but has only two identification ticks and the secondary blades are larger.

The Supadrive® basic shape is similar to Posidriv® and the drive blades are about equal thickness. The main difference is close to a near vertical surface to drive the screws into the drivers. With this superior "bite" screw driving is more efficient, with less come out.[[br]]

Step 99: Spider Drive™

[[br]]"With the Spider Drive™ - Camout is Out! The revolutionary new Spider Drive™ is the most positive internal drive system on the market which eliminates camout. Spider Drive™'s 8 arms or splines and HeadLok's built-in flat washer head for complete lock down, combine for an unbeatable fastening system."

The patent pending Spider Drive™ system was developed for the HeadLok®, both trademarks of OMG, Inc. in Agawam, MA. The eight-lobed design offers the highest level of positive bit engagement and drivability allowing you to drive these screws in with your arm extended with no camout.[[br]]

Step 100: Kinmar® Permanent One Way Security Nut & Screws

[[br]]Another unique high-torque security drive. This patented system is a superior alternative to the shear nut, having the advantage of not leaving any unplated surfaces and not being governed by the shear point, enabling an accurate and reliable torque rating to be achieved.

This fastener can be re-torqued if required. Requires matching tooling to instal. Available in sizes M5 to M12.[[br]]

Step 101: Scrulox®8

[[br]]Scrulox® is another Robertson Invention. An 8-sided (double square) decorative design that can be used with a standard Robertson bit, or for additional torque, a Scrulox®8 bit. These double square fasteners are used on Haulmark trailers and other industrial designs.[[br]]

Step 102: 12-Point Double Hex

[[br]]Double Hex is a fastener specification. It is physically similar but incompatible with triple square and spline drive fasteners. Standard hex keys are compatible as drivers for double hex screws and bolts.

From fellow instructable member lordzion: 12 Point Double Hexagon usually associated with a flange head and in high torque applications where there is a restriction on head size or when space is limited hexagon driving tools eg inside access.

An internal wrenching nut exists, known as an Allenut or Allen nut, is a cylindrical nut that is internally threaded on one side and has an Allen socket on the other side; the outside of the nut is smooth or has knurling on it.

The Allen socket may be 6 point or 12 point (also known as a double hex socket). They are used where hex or square nuts won't fit. Screw sizes from #4 to 1", body diameters from 0.187" to 1.533", heights from 0.179" to 1.532, and socket sizes from 1/8" to 1".[[br]]

Step 103: External 12-Point Double Hex

[[br]]From fellow instructable member lordzion: 12 Point Double Hexagon usually associated with a flange head and in high-torque applications where there is a restriction on head size or when space is limited hexagon driving tools eg inside access. [[br]]

Step 104: 12-Point Triple Square or XZN

[[br]]Triple Square, also known as a XZN are commonly found on German vehicles such as BMW, Mercedes, and Volkswagen. These screws are used in high torque applications such as cylinder head bolts and drive train components. Increasingly, triple square screws are found on other European and Asian makes of cars.

Other names used for Triple Square screws and drivers are "Double Hex", "Double Allen", and "Aircraft Screws". Despite this, "Double Hex" and "Double Allen" are misnomers. The recess in these bolts is actually (as the name suggests) made of three squares, not two hexagons. The corners are 90°, not 120°. As they are not double hexes, an Allen key will not fit them properly.

Common sizes are 6, 8, 10, and 12 mm. Triple square drivers can be purchased at auto parts stores and through automotive tool distributors.[[br]]

Step 105: External 12-Point Triple Square

[[br]]This drive is the inverse of 12-Point Triple Square. They are used in the highest torque applications and military.[[br]]

Step 106: LOX® Recess

[[br]] LOX® technology has already been licensed for use by several distributors, and it is steadily gaining a well-earned reputation as the leading fastener system for high-torque applications. Licensing rights for LOX® are managed by a subsidiary of JJCT Inc. which is headquartered in Alpine, Utah.

In 2001, John "Brad" Wagner patented LOX® recess and driver bit designed specifically for power tools. LOX® features twelve contact points, three times as many as the four points of Phillips and Robertson designs. Twelve points that transfer extraordinary torque while holding a positive engagement drive after drive. In a recent independent test, LOX® screws demonstrated more than triple the torque capacity of square.

The patented LOX® recess easily outperforms every competing drive system on the market, delivering three distinct advantages: 12 points of contact and a near zero degree drive angle, the LOX® recess is engineered to accept torque loads many times higher than competing technologies. LOX® has vertical sidewalls that transfer forces radially, keeping the bit seated and minimizing end load. The near zero drive angle (4°) optimizes torque transmission and eliminates radial stresses, dramatically increasing bit life.

The unique four offset square design four projections that effectively eliminate stripping. These projections maximize bit life while minimizing material waste. Directional stability with multiple, concentric driving surfaces are directionally stable to within less than two degrees which makes this a ideal choice where there is poor access or no direct line of sight to the fastener location.

The design also works as a tamper resistant feature and is suitable for high RPM drives (up to 2000 rpm). Because of its precise fit and evenly distributed forces, the LOX bit life is at least 5-10 times longer than competing systems. Even if the material costs are negligible, workers don't like stopping to replace worn bits. It throws off their rhythm and slows their progress. They often wait until bits are completely worn before stopping to changing them.[[br]]

Step 107: Key-Rex™

[[br]]Bryce Fastener put a great deal of research and development into the Key-Rex™ fastener with the intent to make it a lock. Key-Rex™ shapes are created through an "encryption" process that makes a shape out of millions of variables and defines the "key code" carried by each part. This "key-code" is assigned to an individual user. The millions of key variations ensure that each licensed Key-Rex™ is private and exclusive to the owner. It requires a perfectly manufactured key to operate it. It repels all security bit tips and vice grips.

Used in the most difficult security applications such as voting machines, parking lot lock boxes, gambling machines and city copper security. Sizes available from 3/56-5/8 x 11 (M2-M12)[[br]]

Step 108: Combo Slot - Phillips

[[br]]See Slot Type and Phillips Drives separately. Note the interesting tool made for these screws.[[br]]

Step 109: Combo Slot - Square

[[br]]See Slot Type and Square Drives separately.[[br]]

Step 110: Combo Slot - Square

[[br]]See Slot Type and Square Drives separately.[[br]]

Step 111: Combo Slot - Torx

[[br]]See Slot Type and Torx Drives separately.[[br]]

Step 112: Combo Slot - Hex

[[br]]See Slot Type and Hex Drives separately.[[br]]

Step 113: Combo Hex - Phillips

[[br]]See Hex and Phillips Drives separately.[[br]]

Step 114: Shouldered Security Keys

Produced by at least 3 different companies Diversified Security Systems, Channell Commercial Corporation and NewElectronx

Channell Commercial Corporation
Security StarLock key designed for opening Cable TV PEDs and some MDU lock boxes for apartments.

Slamlock Shouldered StarLock Key
Available from NewElectronx, the Shouldered StarLock Key does not have a pin in the middle of the tool. The Key will fit any 1/4 inch screw driver. Many CATV Telecommunications enclosures use this slamlock/starlock tool to open and lock Shouldered Star Locks / Slam Locks / Lock Box (lockbox) / secured cable line pedestals. The Shouldered StarLock Key is designed to fit most low profile pedestals and can be used on many Cable TVS outside lock box enclosures / boxes. This tool can be used to replace any Diversified, Channell Commercial Corporation, etc security key. Only sold to licensed or authorized field technicians.

They have several configurations available including 4, 5 (2 types), 6, 7, 8 lobes.
The Nutdriver Key is also known as a Sided Slam Lock Star Key, Diversified PED Key, Pedestal Key, Flower Shape Key, Slamlock Nutdriver Point Star Key, Slam Box CATV Security Open Tool, CATV Key Diversifed Star Tool, Cable TV Security, or Cable Box Enclosure Opener Tool.

Step 115: Gamer Drives

The common Gamer Drive group include 2 odd sizes of lobed drives and a small Triwing and Triangle drive.

Nintendo 4.5mm System Security Tool
This is used to open SNES, N64, SEGA, Virtual Boy, Turbo Duo, TG-16 and Gamecube Systems; as well, it is also used with SEGA Genesis (any model) and SEGA 32X Games (cartridges); for easy access to interior parts and vital cleaning that can help your system/games to work perfectly again. Youll have a rather difficult time opening these systems or games without this tool.

Nintendo 3.8mm Gamebit Security Tool
This tool opens NES, SNES, Virtual Boy, Game Gear (SEGA), some Gameboy and N64 Games (cartridges) for easy access for cleaning and repair.

Nintendo Repair Tool
This custome Triwing/Trigram Screw Driver Opens original Gameboy, GBC, GBA, GBA SP, Nintendo DS, Nintendo DS Lite, and Wii systems; GC controller, and GBA game cartridges for repair and cleaning.

Happy Meal Toy Tool
Roomba Robotic Vacuum Cleaners and Happy Meal Toys use a small solid Triangle tip screwdriver.

Step 116: Appendix

==== Glossary of Terms ====

Camout (or cam-out) is a process by which a screwdriver slips out of the head of a screw being driven once the torque required to turn the screw exceeds a certain amount. Frequently, camout damages the screw, and possibly also the screwdriver, and should normally be avoided. However, the Phillips head screw and screwdriver combination was designed specifically to camout, as at the time of its invention torque sensing automatic screwdrivers did not exist.

Phillips is a trademark used for a screw with a head having two intersecting perpendicular slots and for a screwdriver with a tip shaped to fit into these slots.

Recess refers to the shaped socket into which a driver can be inserted

End-Load is the force required to keep the bit to not camout. Low end-load is usually most desirable.

1-Way refers to a screw that is designed for permanently single use only.

2-Way refers to a screw that is intended to be both inserted and removed, used more than once etc.

Referenced Articles

History of Screws and Screwdrivers, by Mary Bellis, About.com

Phillips or Pozidriv? Healey Magazine, Feb 1996

Why did this guy Phillips think we needed a new type of screw by Adams, Nov 24 1989

Screw Drive Systems, Wheeling, IL, Hitchcock Publishing, annual.

A New Design of Screw Head by Brian Rooks, Assembly Automation Vol 21-4, 2001

Furniture screws: primitive to gimlet by Fred Taylor, Discover Mid-America - Aug 2007

Robertson Screws by Ricketts

Hands-On: LOX Screws by Chuck Cage

Testing and Understanding Screwdriver Bit Wear. Thesis submitted to Virgiania Polytechnic and State University.

A New Design of Screw Head by Brian Rooks: Assembly Automation, 2001; Vol 21, Issue 4, Page: 329 - 333.

Inspection-6 Lobe Recess.pdf, article by Joe Greenslade found at www.greensladeandcompany.com

A Light Duty Parallelogram T Nut, version 3; by R.G. Sparber

Robertson Screw and Screwdriver - Incredible Inventions - Cool Canada - Library and Archives Canada, Collections Canada.

Manufactuers & Suppliers of Interest

Phillips Screw Company

Semblex Corporation

S.C.F. Fasteners, Taiwan

Uni-Screw Worldwide, Inc


Seton Security


Bristol Wrench

Complete FastenersBristol Wrench

Free Patents Online

TTAP Screws

Bryce Fasteners

DIY Security Bits.

Cam Car Solutions

Discussion Groups

Discussion Forum; Re Phillips vs Square

Helpful Fools / Does Anybody Know?

Electronics Point Discussion and Advice on All Things Electronic


Instructables feedback of article by several contributing members.

Book on Screw History

Rybczynski,Witold - One Good Turn: A Natural History of the Screwdriver and the Screw, Harper Flamingo Canada, Toronto, 2000, ISBN 0-00-200031-8


Rybczynski, Witold - One Good Turn: A Natural History of the Screwdriver and the Screw. New York: Touchstone, 2000. Good read on topic. It mentions some of the patent and economics of why we have so many of these darn things. "Screw your courage to the sticking-place, and we'll not fail," from Macbeth can go with your obscure party conversation and anecdotes about screws... (from contributor PMstagewarrior)

Step 117: Another Project by Arcticpenguin

Biomedtronix Inc. is a resource of experienced biomedical technical skills.

My Business Formula: Commitment + Excellence = Biomedtronix

My Mission: To provide responsive, cost-effective, quality-driven excellence in technical support of laboratory and medical equipment technology in Eastern Ontario, Western Quebec and beyond.

We can help you with instrumentation and equipment repair and care solutions.

We will tackle almost any equipment challenge as an opportunity.

We are experienced and well versed in mechanical, pneumatic and electronic schematics.

We regularly certify our instrumentation (including temperature & pneumatic) for accuracy.

Check us out at === www.biomedtronix.ca ===

Egon Pavlis - President

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    1 year ago

    Anyone got any idea what kind of screw or bolt this and what kind of screw driver is required? On the back its just a simple flathead.

    Thanks in advance!


    Tip 1 year ago on Step 42

    ChenNan Iron Wire, located in Kaohsiung, Taiwan, also makes the Lotus head drive screws


    Question 4 years ago on Step 33

    I am looking for a Small (1/4" max diameter) driver for the Exterior Triangle Head security screw pictured in Step 33. Does anyone know where i can find one??

    IMG_3051 (007).jpgIMG_2933 (004).jpgIMG_2756 (003).jpg

    4 years ago

    I have seen security screws for sale with a countersunk head and a second head above this that shears off at a specified torque leaving an almost flat head. Only way to get these out would be to grind a slot or else drill the head and use a screw extractor. I beleive the heads are hardened to resist both these methods.


    7 years ago on Introduction

    this came with my 100 piece harbor freight security bit set, I've seen it in other sets as well. does anyone know what kind of screw this goes to?

    mystery bit cropped.jpg

    Reply 5 years ago

    They also market these as wing nut bits but they are better suited to screw-eyes. There are higher quality wing nut drivers that are more cylindrical and notched.


    Reply 7 years ago on Introduction

    These are for driving screw-eyes. They work _fairly_ well. If the eye of the screw eye fits the slot tightly you can start and drive them. If it is loose, you have to get the screw part well-started before finishing the drive with these bits.


    5 years ago

    First time I've encountered the cool name Egon outside of Ghostbusters. And I gather from the signature on the article that you're a fellow BMET.


    6 years ago

    I don't see 'Ferry head' on your list. Strictly speaking, it's a machine screw (bolt) head.


    7 years ago on Step 97

    I think I've seen these on Ikea furniture. If I'm right about that, use of these screws may be part of the reason folks have a hard time putting their furniture together.


    Reply 6 years ago on Introduction

    Do you mean that S - shaped metal rod with hexagonal cross-section? These are supplied with IKEA kits, and are standard size metric "Allen" keys. Any one who has assembled these kits usually end up with a collection. If it gets lost, the IKEA store will happy to give you a spare.


    7 years ago on Introduction

    If you're just getting started I would recommend going to your local craft store and talking to an associate about what's best for a beginner. Or, the best price for a started set is going to be on amazon. Best of luck!!!


    7 years ago on Step 76

    Where can I buy the bit for Penta-Plus ?


    7 years ago on Step 8

    These are great screws with no drive, they look like a rivet or nail head once they are installed. The slightly out of round screw is a good tamper proof deterrent on its own. The special tool makes it even better.

    avsafe tamper proof screws.jpg

    12 years ago on Step 23

    Something similar to this can be found on old (early 80's) Nintendo Game & Watches.
    The long slot sides are parallel, and I guess the hemispherical dip in the middle is to help the screwdriver bit centre in the screw. I presumed they had automated machines installing the screws. I can take macro photos if needed.


    Reply 7 years ago on Introduction

    Similar to which? This doesn't sound like the Nintendo gamebits I encountered. I would very much like to see those photos.


    7 years ago on Introduction

    I got these at the Home Depot for I think $3 the Milwaukee ECX 1&2 supposedly their only sizes, package says for electrical fasteners, these have their impact driver compatible shank and looks like the "step110: combo slot - square"

    milwaukee ecx 1&2 cropped.jpg

    Reply 7 years ago on Introduction

    photos by me feel free to add them to the list


    10 years ago on Introduction

    I have a tool box of many shaped bits I have collected. Some I have modified and hardened. I have various types of screw extractors and pliers. It also contains a cordless Dremmel with the cutting disks as mentioned by some. I also have Super Glue and fast setting JB Weld in it. The latter gets so hard it can be machined. I have mixed some up, filled the offending screw head and stuck a bit in it and let it harden and then backed the screw out or filled the head and then cut a slot in the hardened JB Weld and used a straight blade.

    It is not a large tool box. It is an old tackle box actually. All of the bits fit in a roll up canvas Skil bit assortment set I got many years ago...it came with 5 of each of many types of bits and drills in it. About 320 screw bits and drill bits in all. Now it has just the various types of screw bits, some extractors, and the drill bits are just a set of cobalt drill bits for screw drilling, the others are long gone giving their space to more screw bits. When it is rolled up it is about a foot long and about 3" in diameter.

    It doesn't take much space to build up a kit. I used to hit specialty tool shops for equipment I worked on and trained techs to repair. I was in electronics, but bought tools to make tool sets for our field techs, if I saw some odd bits while out and about and they were not much in cost I'd pick them up for myself.