Flash butt welding is a process designed to produce a forge-type butt weld between two metal pieces of similar shape.It is used to join ends of rods, bats,strips,rings,tubes,forgings and fitting.The pieces to be joined are clamped in fixtures which are connected to the secondary of a welding transformer.One of the clamp fixtures is mounted on a slide which is programmed to move toward the stationary clamp at a controlled rate. During this movement the transformer is energized and as the work pieces touch.Welding current flows.This flash process generates heat in the work pieces.