Although there are many kinds of tapping screw, they al […]
Although there are many kinds of tapping screw, they all have the following main characteristics:
(1) Carburized steel is usually used for manufacturing (99% of total commodities). It can also be made of stainless steel or non-ferrous metals.
(2) It is necessary for commodities to undergo heat treatment. Carbon steel tapping screw need to be carburized, stainless steel tapping screw need to be treated by solution hardening. In order to make the self-tapping screw reach the mechanical function and use function required by the standard.
(3) The product has high surface hardness and good core resistance. That is "soft inside and rigid outside". This is a major feature of self tapping screw function request. If the surface hardness is low, it can not be screwed into the matrix; if the core has poor resistance, it can not be used as soon as it is screwed off. So "soft inside and rigid outside" is the requirement of tapping screw to satisfy its function.
(4) The appearance of commodities requires surface protection, usually electroplating. Some products need phosphate treatment (phosphating). For example, most of the self-tapping screw of wall panels are phosphating.
(5) Choose cold heading technology to produce. It is recommended that high-speed cold heading machine and high-speed wire rubbing machine or high-speed planetary wire rolling machine be used to ensure the quality of goods. The head of self-tapping screw produced in this way is well formed and the thread quality is high.