Arc stud welding, often referred to as drawn arc stud welding is a very specialized welding process to quickly attach fasteners, the arc weld studs, to one surface of the workpiece.
The benefits of this process are important to consider, particularly on large projects or on structural building jobs. With the weld stud welded to one side of the workpiece, there is no need to access both sides of the workpiece and attaching materials is very simple and easy.
Additionally, using the drawn arc stud welding process, it is very fast and, with the heat concentrated through the use of a ferrule around the base of the arc weld studs, the weld fillet is neat and contained. There is also no visible sign of the welding process on the other side of the workpiece, which is essential in shipbuilding, building tanks, and storage containers or other types of structures.
Drawn Arc Vs. Resistance Welding
With resistance welding techniques it is possible to weld fasteners to the surface of a workpiece, provided both the workpiece and the fastener are of a suitable material. This is a different process requiring the welder or automated system to use a material that is melted to create the weld or the bond between the two metals.
Withdrawn arc stud welding, an electric arc is developed between the arc weld studs and the metal surface. This melts both in fractions of a second, then drives the stud down into the molten metal, creating a complete weld that is complete, free from leaks and also resistant to pressure.
Unlike resistance welding where the weld is formed from the exterior of the fastener, when using the arc weld studs the entire base of the stud and the matching area under the fastener fuse, creating a stronger bond. With full automation or semi-automation in the systems, the weld studs can be identically welded. The use of the ferrule or ceramic ring around the base of the stud holds the molten metal in place, allowing for stud welding on flat, rounded as well as angled surfaces.