Abstract: A small-sized gas pressure welding machine for rails comprises a pressure application unit and an excess metal punching unit. The pressure application unit includes a positioning bed disposed along the rail feet of rails to be welded together, a movable pressure application clamp mechanism provided at one end of the positioning bed and a stationary pressure application clamp mechanism provided at the other end of the positioning bed. The movable clamp mechanism clamps the rail foot of one of the rails and provides an abutting pressure. The stationary clamp mechanism clamps the rail foot of the other rail and receives the abutting pressure.

Abstract: A gas pressure welding machine comprises a movable clamp means for clamping one of reinforcing rods to be joined together, a stationary clamp means for clamping the other reinforcing rod, a punching die for punching-shearing a bulge being formed around a joint portion of the reinforcing rods, and a key connection mechanism for detachably connecting the movable clamp means and the punching die, whereby the reinforcing rods are subjected to pressure butt welding to form a bulge around a joint portion thereof and the bulge is immediately punching-sheared under red heat by the punching die.