A self-tapping screw is a screw with a drill bit. It is constructed by a special electric tool, and the drilling, tapping, fixing and locking are completed at one time. What are the main characteristics of self-tapping screws?
Although there are many types of self-tapping screw
s, they all have the following main characteristics:
(1) It is generally made of carburized steel (99% of the total product). Also available in 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 solution hardened. In order to make the self-tapping screw meet the mechanical properties and performance required by the standard.
(3) The product has high surface hardness and good core toughness. That is, "inner softness and outer rigidity". This is a major feature of the performance requirements of self-tapping screws. If the surface hardness is low, it cannot be screwed into the matrix; if the toughness of the core is poor, it will break as soon as it is screwed, and it cannot be used. Therefore, "inner softness and outer rigidity" are the requirements for self-tapping screws to meet the performance requirements.
(4) The surface of the product needs surface protection treatment, generally electroplating treatment. Some product surfaces require phosphate treatment (phosphating). Such as: wall panel self-tapping screws are mostly phosphating.
(5) It is produced by cold heading process. It is recommended to use high-speed cold heading machine and high-speed thread rolling machine or high-speed planetary thread rolling machine to ensure product quality. The self-tapping screw produced in this way has a well formed head and high thread quality.