Drawn Arc Method

Drawn Arc Method is a base of arc stud welding method.
In this method, direct current welders are usually used.

The theory is shown in Chart-3.

First, insert stud into Chuck of the stud welding Gun and put ferrule made of heat-resistant ceramics around the welding base of the stud, then press stud and ferrule onto the base metal.
Next, when you push the Gun Switch of the welding Gun, Control Circuit starts operation, pilot arc runs between the base metal and the stud, at the same time Solenoid Coil inside the welding Gun is magnetized, stud is pull apart from the base metal, then pilot arc is generated between the base metal and the tip of the stud.
Soon after this, large current for main arc runs,
Main arc continues for the time setup by timer in advance,
Magnetization of the Solenoid Coil is cut off, then stud is automatically pushed back into the molten pool of the base metal by repulsion of the spring inside the welding Gun.
Break and remove the Ferrule, then welding work finishes.