Drilling Metal With a Drill Press




I'm keen on a job well done: using tools safely and effectively so they perform in a beautiful way and for a long time.

And so I offer to you what I know about drilling holes in metal with a drill press.

(When you're planning a project, resist the urge to say, "... and then just drill a hole in it"! Good practices will guard the life of your tools. Also, you'll learn a LOT about the qualities and "feel" of your materials.")

And, as ever, I put this together at Techshop Detroit www.techshop.ws. It's a great place, I tell ya what. Come in and make... ANYTHING!

Step 1: Tools and Materials

Talking about the tools and materials you need for this process is a little like asking, "what's the shape of water?" Just depends on the circumstances!

More to the point, you'll need metal material to drill through; the right bit for the kind of hole you want to drill; a method for centering your drill bit in your intended hole; AND ADEQUATE TOOLS FOR HOLDING MATERIAL SAFELY IN PLACE.

This is a kit of tools and materials you might assemble for metal-hole-drillin'. The things circled in green are what we MUST have to drill a hole in steel, strictly speaking.


- Ruler/straight edge. Steel is durable; durable = accurate

L to R:

- Scrap angle iron

- Fine point permanent marker

- Center punch

- Drill bit - common twist drill bit; find this kind at the hardware store - HSS (High Speed Steel) is common and effective

- Square

- Tape Measure

- Wrench and Rite Hite clamps for holding work.

Step 2: Preparation Fast-Forward

First you're going to mark where you want to drill holes.

Then you're going to make center punch marks to help your drill bit safely do its job.


Step 3: Anatomy of a Drill Bit

From top to bottom we have:

- The shank: Solid portion of the bit meant for gripping in drilling tools. Heat-treating a drill bit is controlled so the shank stays softer while the cutting end becomes hard; this helps with the grip. You'll find the diameter of the bit stamped on the shank

- The flutes: spiraling channels which carry away drilled material or "chips."

- The cutting edges and the chisel tip: the edges are sharp and angled to scrape and lift material. The chisel tip (or web) is a flat space between the edges to support the cutting edges and the bit point in general.

Step 4: Load the Drill Bit in the Drill Press

A drill press has a chuck on it that holds cutting tools. Usually this is a Jacobs Chuck, with jaws that open/close when you twist the outside of the chuck.

"Chuck" your drill bit in. Make sure it's centered between the chuck jaws. I like to chuck my bits in just about the flutes, as shown below. This makes the most of the shank and supports the bit as much as possible.*

Use the chuck key to tighten the bit in (again, be sure it's centered in the jaws.) Tighten in one place around the chuck, then tighten from a second direction. That way you know the jaws are evenly engaged.

*I've heard arguments to chuck the bit higher on the shank; the shallowest I'd go is just above the size stamp.

Step 5: Center Your Bit

This is a very important step. When you're working with metal, you can't just hold with one hand and drill with the other. Abandon any ideas of "just really quickly" or "one little counter sink" or anything that suggests that being safe might be a waste of time.

PLEASE don't ask for corroborating stories.

Now locate the drill in the center of the hole. Lower the quill on the drill press and "touch down" into the center punch mark. You should feel the bit nestle in, with lighter material actually shifting over and centering itself. You're looking for the chisel tip to sit within your center punch mark. When it looks good from one angle, swing around and look from another angle just to be sure.

Step 6: Clamp Your Work

This step can be done in many ways, but it's essential. Drilling metal is slow and requires of force from the drill press. If the bit grabs your material instead of cutting it, the material can spin or launch. And between you, the material, and the drill press - you're going to sustain the most injuries.

By contrast, a well-clamped drill operation is nearly fool-proof.

I used Rite Hite clamps These clamps are bolted to threaded rods which are in turn anchored to slots in the drill press table. C-clamps are fine too, just make sure they're seated sturdily and tightened down.

Step 7: Drill!

A pre-step to drilling is to make sure the motor speed on your drill bit is correct. A VERY loose rule of thumb for this is 500rpm or slower is good for mild/"hardware store" steel. In tandem with this rule is "the smaller the bit, the faster you can go."

Check for the RPM setting that matches your material and bit choices, then set your press.

When you're drilling, use both hands on the quill feed (that's the wheel that lowers the bit.) If you're worried that your material might move if you don't have a hand free, better re-clamp!

Ease the bit into your work, and after you've cut for a few moments, lighten up on the bit to cut chips free. Keep this "pressssss-lighten, presssss-lighten" rhythm until you're through the material.

How will it feel? With decent steel and the right RPM setting, you'll hear a "shuh-shuh" sound, maybe a low scraping sound, but the cutting action will be smooth and leisurely. Any rattling or smoking means you're not working optimally; squeeling or grinding means you'd better stop and recheck your configuration.

and... YOU'RE DONE!

Step 8: Clean Up

Vacuum/sweep your chips. Please. Respect yourself, respect your tools, respect those who share the space.



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    28 Discussions


    1.) Para perforar con la seguridad de que la broca no pierda el filo usar Aceite Soluble para Corte.

    2.) La velocidad del taladro es importante. A más diámetro de la broca menor velocidad.

    3.) Para hacer orificios bien redondos y no triangulares o pentagonales les mando un secreto desde el sur del continentea saber.

    a.)Cortar un trozo de tela de jeans, aproximadamente 40 mm x 120 mm. Hacer cuatro dobleces con el trozo de tela.

    b.) Perforar con una broca de diametro menor el orificio en el perfil de hierro. A continuacion, realizar sucesivas perforaciones de distinto diametro siempre mayor colocando entre la broca y el perfil de hierro el trapo doblado en cuatro pliegues.

    c.) A continuación y con la velocidad que usted ve que una fina viruta enrrulada sale desde el interior del trapo. No detenga la perforación, no tenga miedo que biene ok.

    Ud casi no se dará cuenta que traspasó el material de hierro. Cuando saque la broca verá que ha realizado un perfecto orificio redondo.

    d.) Si en el proceso explicado en apartado c.) usted nota que la broca se sacude, esto indica que esta haciendo un pentagono y no un orificio redondo. Pare el proceso, levante la broca y el trapo, observe.Verá sin dudas un triangulo o un pentagono. Realice un nuevo doblez en el trapo y comience de nuevo. No utilice el trapo perforado, siempre la broca tiene que comenzar con un sector del trapo nuevo. Al finar obtendrá orificios perfectos.

    e.) Este proceso es muy útil cuando uno tiene un taladro de mano y no dispone de un taladro de banco. Pero use con extrema prudencia, ya que en algunas circunstancias la broca se traba en el material y usted se rompe la mano. Tomar con FIRMEZA el taladro.

    El secreto de usar un trapo de jeans en cuatro o más dobleces implica que el trapo propiamente dicho rellena las partes sin filo de la broca y permite que este gire suavemente en un plano compensado por el trapo. Luego la broca no bascula y no se produceán los indeseados orificios pentagonales.

    Espero pueda entender y aplicar estos consejos. Veo que usted es muy nuevo en este oficio y no me agrada los comentarios de aquellos sabios que le indican como poner la traba para fijar el ángulo de hierro.

    Por último. Usted puede perforar todo tipo de materiales con este sistema, pero si perfora plásticos y ó acrílicos tenga en cuenta que el trapo toma temperatura y suele dañar el material que usted está perforando. Moje con agua el trapo y perfore con pequeños golpes de gatillo. En estos casos no utilice una broca muy afilada. Para los plásticos las brocas desgastadas, casi sin filo son excelentes ya que al traspasar el material no se trabará ni romperá el material que está perforando.

    Desde el sur del planeta le mando un gran saludo y a perforar sin miedo.



    7 years ago on Introduction

    I don't want to be too boring but the most important things for me drilling steel are the surface speed, and the drill bit web thickness.

    Surface speed is calculated with the following formula:

    PI * DIA. * RPM / 12 = SFPM

    PI = 3.1415927....
    DIA = Drill bit diameter
    RPM = Revolutions Per Minute
    SFPM = Surface Feet Per Minute

    But we usually know the values of everything but RPM so to solve the equation for RPM I find this formula more useful:

    RPM = SFPM * (3.8197186  /  DIA.)

    12 / PI = 3.8197186

    The target surface speed for drilling mild steel is 50 - 80 SFPM

    Larger drill bits have a chisel point that does not really cut through steel like the bit's cutting lips do. This amount of material should be drilled out first by step drilling with a smaller diameter drill bit.

    Some cutting coolant and lubricant never hurts when drilling steel either.

    I think you should get yourself a drill press vise. They make holding steel to drill it a lot easier than your hold down clamp does. I have a couple:


    I do most drilling in this vise with parallels in it though:


    On the left in that picture you can see some of my lubricants and coolants in bottles too. For drilling steel I mostly use emulsified oil, and lately Rapid Tap. It is easier to clean up.

    6 replies

    Reply 1 year ago

    I think for this application pi ~=3 will work just fine :-)


    Reply 1 year ago

    If you take a close look at your smaller bits, you will find they have a chisel point too. It's just smaller.

    1/2" diameter is 4 times the area of 1/4". Maybe 1/4 the speed would be more appropriate.

    No, not boring at all. It's important to have a grasp of the physical science behind these procedures, esp. since even experts have different RPM charts, depending on what they want to get out of their tools.

    I can't claim I understand the science behind it all, but I've used it enough now I am mastering a bit of the art as a result. Enough that I've scoffed at a few experts charts along the way. Though in the defense of experts on a lot of jobs the best speed differs as a result of other variables.

    With these formulas you could even get the extra performance out of your TiN coated yellow bits I see you have. I think they can run 10% faster than uncoated bits can. Something silly like that :)

    But hey, without these formulas how could you ever benefit from the performance enhancement you paid for? In any event these formulas do work, and like you said those experts charts appear to be all over the map at times. So run your own numbers then work with something you know what you have.

    On more challenging jobs where you're not just drilling through the legs of lightweight mild structural steel these formulas can become more valuable.


    1 year ago on Step 7

    You mention safety frequently (good!) but do not once mention eye protection, and don't include it on your list of essentials!

    What about lubricants? I understand oil is sometimes recommended. What if your work gets really hot, should you let is rest for a while? What about stainless steel, how do you prevent work hardening?

    You seem to have much knowledge and experience of the subject but cruelly stop your instructable at just about at the limit of my knowledge. I've never seen "Rite Hite" clamps, though, I'll look into that.

    Eye protection: I'd guess if someone wants to "just drill a hole" and doesn't have time for safety this one time that's a typical area to skimp. I know because I've done it. That was before retinal detachment surgery (nothing to do with a workshop accident) turned out not so great (I can see with the eye, but only the first line or two of the chart on a good day) and my eye doctors started lecturing me on taking good care of the remaining good eye. I know from time spent at a retina and vitrious surgery practice that if a tiny flying shard were to work its way into the inner eye and someone had to go in after it, how it turns out in terms of vision for the rest of your life is a crap shot.


    1 year ago

    For BRAMA: The fabric balances any differences in grinding between the two propellers that make the tip unstable when the hole is started


    Tip 1 year ago

    Drilling a smaller 'pilot' hole will give better accuracy for all but the smallest drills;and is very important when using larger size drills,it helps guide the drill in a straight line instead chattering about until it has something to 'bite' into.

    If your drill bit produces trianglar holes re-clamp it in the chuck a fraction of a turn round;sometimes the stamped size marking causes it to sit unequally in the chuck,so can swarf, grit, or burrs caused by the drill getting 'spun' previously in a chuck.

    Keep the chuck clean with thin oil. (which should ALWAYS be used to lubricate the spot the drill lands on BEFORE drilling,and more part way through if it burns off! high-speed steel 'HSS' drills can cope with heat,upto a certain level ! but oil gives them an easier life; by reducing abrasion and so creating less heat.


    1 year ago

    Didn't see it mentioned, but good lighting is a must. Industrial grade machines almost always come with worklamps already fitted. A cheap option is to use an adjustable LED ceiling spotlight or even a decent torch to really light up where you are going drill. As an alternative to a centre punch, use a small ~ 2-mm bit to spot where you want to go in. Where space permits, I push the bit as far up the chuck as it will go to reduce wobble. And always respect the machine and bits - a large diameter bit that snatches can do a lot of damage


    Tip 1 year ago

    Only use sharp drill bits. When drilling larger holes start with a small bit and work up in steps to the final size. This will give a more accurate hole and put less strain on your drill press.

    Definitely use cutting fluid when drilling steel.


    Tip 1 year ago

    Round holes?

    Have you noticed the a hole drilled in steel say 3/8" or larger are slightly triangular.

    If you need the hole to be round, drill through a piece of cloth. Not too big a piece as it will spin and can catch. Someone else may be able to explain why this works, I can only say I have drilled many large holes and it works each time.


    6 years ago on Step 7

    I've heard about the use of oil / lubricants to help the process.
    Are these required?

    1 reply

    Reply 1 year ago

    Not really "required" but helps promote longer drill and drill bit life, makes a better hole and prevents the metal from getting as hot.


    1 year ago

    You must be from "down under". I knew that water swirled backwards in toilets down there and I guess clamps get installed backwards too. My floor standing drill press goes down to 80 rpm. It prolongs drill bit life. I use Rapid Tap for steel and WD-40 for aluminum. Give me slow and a lot of force any day.


    Tip 1 year ago

    Probably one of the most important things which should be included in this tutorial when drilling steel is to use some type of cutting fluid or at least any type of oil. This will go a long way in helping keep the bit lubricated and cool. Once you get a HSS drill bit too hot, the cutting edge will be toast and will then either need to be resharpened or replaced.