1. It is generally made of carburized steel (99% of the total product). It can also be made of stainless steel or non-ferrous metals.
2. The product must be heat treated. Carbon steel self-tapping screws must be carburized, and stainless steel self-tapping screws must be solid solution hardened. In order to achieve the mechanical properties and performance of the self-tapping screws to meet the standard requirements.
3. The surface hardness of the product is high and the core toughness is good. That is, "inner soft outside just." This is a major feature of the performance requirements of self-tapping screws. If the surface hardness is low, it will not be screwed into the base; if the core has poor toughness, it can not be used once it is broken. Therefore, "inner soft outer" is the requirement that the self-tapping screws meet the performance requirements.
4, the surface of the product needs surface protection treatment, generally electroplating treatment. Some products require phosphate treatment (phosphating) on the surface. Such as: wall panel self-tapping screws are mostly phosphating.
5. Production by cold heading process. High-speed cold heading machines and high-speed wire rolling machines or high-speed planetary rolling machines are recommended to ensure product quality. The head of the self-tapping screw thus produced is formed and the thread quality is high.