For some heads, resistance welding technology is often used for processing. However, when using this technology, there are some common sense points that everyone needs to know. The following will explain them to you in detail.

　　When the resistance welding core of the head is formed, it is always surrounded by a plastic ring, and the molten metal is isolated from the air, making the metallurgical process simple. The heating time is short and the heat is concentrated, so the heat-affected zone is small, and the deformation and stress are also small. Generally, there is no need to arrange correction and heat treatment processes after welding. During welding, the head is usually deformed after welding. If the deformation exceeds the allowable value, it will affect the use. The main reason is the uneven local heating and cooling of the welded part. Because during welding, the welded part is only heated to a high temperature in a local area. The closer to the weld seam, the higher the temperature and the greater the expansion.

　　Therefore, when the head and the electrode are set, the resistance of the head depends on its resistivity. Resistivity is an important property of the material to be welded. Therefore, metals with high resistivity have poor thermal conductivity (such as stainless steel), while metals with low resistivity have good thermal conductivity (such as aluminum alloy). In conclusion, when spot welding stainless steel, it is easy to generate heat but difficult to dissipate it; when spot welding aluminum alloy, it is difficult to generate heat but easy to dissipate it.