In general, with small diameter metric weld stud sizes, as well as with standard diameters used more commonly in the United States, a capacitor discharge process will be used to create the weld.
The Benefits
CD stud welding is a very effective way to create a solid, durable and aesthetically effective type of weld. It is done very fast, so there is limited heating of the base metal, resulting in extremely limited burning, marring or distorting of the surface of the metal immediately around the weld and no visible signs on the opposite side.
In most applications, CD welding using metric weld stud sizes are used with smaller electronic components, hardware and tool handles, brackets, electrical devices and cases as well as for jewelry. However, it can also be used for installing cap head pins for insulation on metal sheets and housings, making it a standard option in the HVAC industry.
Tip Ignition
In most cases, even with the small size of metric weld stud options, you will note there is a small tip that is cylindrical in shape on the base of the stud. The tip will make contact with the surface of the metal, and then, as the current is applied, the circuit closes, causing that small tip and the immediate surface of the base metal to melt instantly.
There is the option to use a welding with contact or welding with gap process. Both produce the same discrete and reliable weld as well as a very quick process. Either option will allow for the use of standard or metric studs in standard and custom sizes in mild steel, aluminum, and stainless steel. In jewelry making and other applications, other alloys can be used, but their use is much less common in standard industrial fabrication processes.