Introduction: Improving Metal Connections Werkplaats IDC

Hi, we are Arnout and Martijn (3IPO)

In this instructable you'll be able to learn different metal connections & tips and tricks to work faster.

We will show you how to rebuild simple tools to achieve this goal and explain the settings of specific machines.


Metal Connections that will be discussed:

1) How to use Bolts, nuts and screws in prototypes.

2 ) Mechanical Connection Through Bending.

3) Practical tips to use Rivets.

4) Tips & tricks in Welding.

5) Tips & tricks in Spot welding.

Step 1: How to Use Nuts, Bolts & Screws in Prototypes

Some explanation

1) A nut is a type of fastener with a threaded hole. Nuts are almost always used in conjunction with a mating bolt to fasten two or more parts together. The two partners are kept together by a combination of their threads' friction (with slight elastic deformation), a slight stretching of the bolt, and compression of the parts to be held together. ( Pic.4 )

1.1) A locknut is a nut that resists loosening under vibrations and torque. Elastic stop nuts and prevailing torque nuts are of the particular type where some portion of the nut deforms elastically to provide a locking action. ( Pic.4 )

1.2) Awasher is a thin plate with a hole that is normally used to distribute the load of a threaded fastener, such as a screw or nut. Washers usually have an outer diameter (OD) about twice larger than their inner diameter (ID). Washers are usually metal or plastic. High-quality bolted joints require hardened steel washers to prevent the loss of pre-load due to Brinelling after the torque is applied. ( Pic.3 )

2) A screw is a type of fastener, sometimes similar to a bolt, typically made of metal, and characterized by a helical ridge, known as a male thread (external thread) or just thread. ( Pic.12 & 13 )


Making a nut and bolt connection:

  • mark the metal sheet ( use a scriber or a pen Pic.14 )
  • drill the holes ( Pic.2 )
  • Deburr the holes.
  • insert the bolts through the holes
  • screw the nut on the bolt ( Washers can be used to protect the metal or other materials )

Making a countersunk screw connection:

  • mark the metal sheet
  • drill the hole
  • use a countersink bit (or a bigger drillbit) to create a conical hole
  • use a screwdriver to drive the screw in


  • If you don't have a scriber or pen just take a small metal bar and create a sharp point using a big grinder machine.
  • Use a point of Impact to make sure you drill perfect. ( Pic.1 )
  • Don't always waste time to deburr the holes. Sometimes you can take a bigger drill and just deburr it by hand.
  • When attaching the nut/bolt you need 2 wrenches. If you don't have 2 wrenches you can use the vise to hold the nut or bolt in place ( Pic.5 & 6 )

Step 2: Mechanical Connection Through Bending

A mechanical connection can be made without any additional material.

Now we will show you how to make a closed and strong connection In this case 2 sheets were bend using a sheet bending machine.


  • place the overlap in the machine ( Pic.2 & 3 )
  • bend as far as possible
  • use a wooden block to press the bended parts further down
  • place the bended parts between the machine
  • bend as far as possible


  • Use the handle to open and close the machine and lock the plates u want to bend. ( Pic.2 & 3 )
  • Do not bend to far if it's not possible because you can allways finish the bending with a piece of wood. ( Pic.6 & 9 )
  • If you can't press the parts together completly, you can use a vise to make it easier. ( use cardboard or wood to make sure you don't damage the plates. )

Step 3: How to Use Rivets

A rivet is a permanent mechanical connection. It's used for many things and is a crucial part in aircraft building.

To use a rivet you'll need a rivet gun (mechanical or pneumatic)

  • start by drilling holes (in this case 3mm)
  • put the head of the rivit through the holes of 2 sheets
  • place the gun over the shaft of the rivet
  • use the rivet gun to 'pop' the rivet


  • You can also make a hinge by creating some space between the 2 sheets. This can be done using an extra sheet or a piece of cardboard. Remove this piece after popping the rivet.
  • Also make sure to deburr the holes because this can effect the clamping of the plates.

Step 4: How to Weld Parts

Some explanation

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal. In addition to melting the base metal, a filler material is typically added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that is usually stronger than the base material. Pressure may also be used in conjunction with heat, or by itself, to produce a weld.


  • You will need a welding helmet and a side cutter. ( Pic.4 & 5 )
  • Now we will make sure we put on the gas and the machine.
  • Also we need to use the mass clip. Make sure you attach the mass clip to the steel table
  • Put the 2 parts that you want to weld on the table.
  • Now you can weld the parts.


  • For the welding machine in the idc center you need to make sure the settings are correct. Because otherwise you wil burn holes in your part or you will not weld the parts good enough. This is a trial and error process. Always test your settings on a scrap part before you start welding. For thin plates you have to make sure the settings are LOW and the wire feed is correct. You can hear a ticking noise, this must be a continuous sound to make a good weld.

- Wire feed ( Pic.3 ) The red one!

- On switch is the 0/1 ( 0= off and 1= on ) ( Pic.2 )

- Setting button weldpower is the red button above the on switch( Pic.2 )

  • A weld can be thick and needs to be finished with a polisher/grinder machine
  • First you will make sure you can remove the thick weld as fast as possible. This can be done by using a stone disc ( Pic.13 ) result is ( Pic.16 ) MAKE SURE TO WEAR SAFTY GLASSES!!
  • To finish the weld you can now remove the rest of the weld with the polish disc. Be careful and don't press too hard because otherwise you will weaken the weld and it can break. ( Pic.20 )

Step 5: Spot Welding

Spot welding is a very useful technique to quickely connect to pieces of metal (sheets/rods).

Aluminum sheets can be used but are not ideal as it doesn't conduct like other metals.

Connecting 2 sheets:

  • Overlap 2 sheets
  • place the overlap between the 2 electrodes
  • use your foot to press the controlbar down until the noise stops
  • repeat as many times as necessary

Controlling the power and time are critical for good spot welds. Test the settings using scrap parts.

Connecting rods:

  • Overlap 2 sheets
  • place the overlap between the 2 electrodes
  • use your foot to press the controlbar down until the noise stops
  • repeat as many times as necessary

Using low power will connect the rods on top of each other, higher power will melt them together.


  • Welding aluminium is not easy! so for point welding we need to put the settings on Max power and a short time of welding.
  • For steel the settings need to be arround 5 for power and the time arround 4.