Stud Arc Welding and Drawn Arc Welding

Stud arc welding replaces the conventional welding stick or wire with a threaded fastener stud. The stud fits into the end of specialized stud welding gun. An arc is struck between the fastener stud and the work piece, which fuses the stud to the work piece's surface. Drawn arc, capacitive discharge, internal resistance, or other processes are used to generate an arc or fuse metal. Similar processes can be applied to weld a thread nut to a work piece.

In drawn arc welding systems, an arc is struck between the fastener and work surface, the fastener is then lifted and plunged into the molten material after a specified time. In capacitor discharge welding, a bank of capacitors is charged and then the discharged current is applied across the joint between the work pieces. Usually, one of the work pieces has a nip where arcing is initiated. The arc spreads radially out along the surfaces to be joined. Once the surfaces are melted, a pneumatic cylinder, spring, or another mechanical actuator forces the surfaces together.