Resistance welding refers to the method of using the resistance heat generated by the current passing through the welding parts and the contact points as the heat source to heat the parts locally and pressurize the welding process at the same time.Welding, do not need to fill the metal, high productivity, small deformation of welding parts, easy to achieve automation.

Resistance welding is a welding method that makes the workpiece under a certain electrode pressure and uses the resistance heat generated by the current passing through the workpiece to melt the contact surface between the two workpieces and realize the connection. Larger currents are usually used. To prevent arcing on the contact surface and to press the weld metal during welding, pressure is always applied. In this kind of resistance welding, the surface of the welder is of Paramount importance to obtain stable welding quality.Therefore, the contact surface between electrode and workpiece and between workpiece and workpiece must be cleaned before welding.

When the workpiece and electrode are set, the resistance of the workpiece depends on its resistivity. Therefore, resistivity is an important property of the welded material. Metals with high resistivity have poor thermal conductivity (such as stainless steel) and metals with low resistivity have good thermal conductivity (such as aluminum alloy). Therefore, spot welding stainless steel is easy to produce heat and heat dissipation is difficult, spot welding aluminum alloy is difficult to produce heat and heat dissipation is easy.Spot welding, the former can use a small current (thousands of amps), the latter must use a large current (tens of thousands of amps).