Tapping screw to use more advanced on some than ordinary screw, tapping screw drilling without tapping holes, using different screws and general, head is sharp, tooth pitch is bigger, and a chipless silk attack is a bit like, you can not tapping screw directly into, metal and plastic usually use this method. There are many kinds of self-tapping screws, but they have the same characteristics.
1. Generally, it is made of carburizing steel (99% of the total product). It can also be made of stainless steel or nonferrous metals.
The product must be heat treated. Carbon steel self-tapping screws must be carburized, and the stainless steel self-tapping screws must be treated by solid solution hardening. The mechanical properties and performance of the self-tapping screw to meet the standard requirements.
3. The surface hardness of the product is high and the core is good. That is, "soft outside." This is one of the characteristics of the performance requirements of self-tapping screws. If the surface hardness is low, no wring into the matrix; If the core toughness is poor, one wring off, also cannot use. So "inner soft outside" is a self-tapping screw to meet the requirements of performance.
4. Surface protection is required on the surface of the product, which is usually electroplated. Some product surfaces need to be treated with phosphate (phosphating). The wall board self-tapping screw is mostly phosphating.
5. Production of cold heading technology. It is recommended to use high speed cold header and high speed thread rolling machine or high speed planetary thread rolling machine to ensure product quality. The production of the self-tapping screw has a good shape and high thread quality.