frequency furnace, thus resulting in more evenly smelted raw materials, morecompacted crystal , controlled temperature of metal solutions and thermostat smelt. The movement of the solution is increased during casting, with goodexhaust effect, which increases the strength and service life of the gun arms.The part of electrodes is processed by cold bending process, and the strength of raw materials is reserved after deformation.The cylinder of the welding gun is made of aluminum alloy profiles, which have a tighter structure. The intensity is higher and the level of surfacefinish is better compared with the traditional casting cylinder, therefore reducing the frictional resistance, enhancing the pressure output efficiency, extendingthe service life and improving the abrasive resistance of gasket effectively. Additionally, the piston rod surface of welding gun is processed by hardchrome- plated, resulting in good intensity, higher level of surface finish, and improved service life of the piston rod and gasket.The open-close way of the split type welding gun includes X-type and C-type, and also can be classified as manually mechanical double-stroke weldinggun and pneumatically mechanical double-stroke welding gun as per the stroke opening way.All spare parts of welding gun have been standardized, shortening the design and production cycle.