Permanently attaching fasteners to a metal workpiece has advantages over using fasteners that require a drilled hole. One of the biggest differences is that the welded fastener only requires access to the one side of the workpiece, something that is important on large pieces and when installation is in challenging locations for access to both sides.
Additionally, and this is important in many type of manufacturing and fabrication, the weld fasteners are only visible on one side of the metal workpiece. The other side is perfectly smooth and unblemished, providing the necessary cosmetic or aesthetic appearance required.
There are two different ways to process weld fasteners of any type. This includes arc welded and resistance welded.
Resistance Welding
Under the category of resistance welded fasteners there can be projection welding or spot welding involved. Projection welding includes using heat on the specific projections on the fastener to bond it to the metal surface. This is typically done with a press welder.
Spot welding includes a larger area of current that covers the entire area of the faster with the electrode. This creates a molten area where the base metal and the fastener fuse.
Arc Welding
With weld fasteners produced through the drawn arc welding process, an electrical arc is generated between the workpiece and the fastener. This creates the molten pool of metal from both the fastener and the base metal. The fastener is then pushed into the liquid and a solid bond is formed.
During this process a ferrule, a ceramic ring, is used to contain the molten metal and to concentrate the heat generated from the arc. After the molten metal is cooled the ferrule is broken off.
Arc welding can be completed very quickly, economically and with high degrees of precision. It also allows for full mechanization of the process, further allowing for a more cost-effective production option.
