Pay attention to the details of the heat treatment process for metric thread tap

2025-09-01 14:51:20

In the heat treatment production process of metric Thread tap, due to people often neglecting some details, the heat treatment of metric thread tap is distorted, even cracked and scrapped, resulting in a high scrap rate and significant economic losses. Therefore, the following issues should be noted in production:

1) In order to reduce the tendency of distortion and cracking during quenching of metric thread tap, especially for metric thread tap with high precision requirements, the mechanical processing stress generated in the previous process should be eliminated.

2) The materials used to manufacture metric thread tap must undergo quality inspection before mechanical processing. The microstructure of the materials should be spheroidized, with small and evenly distributed carbides. If the microstructure of the material is lamellar pearlite and the carbide size is too large, the unevenness is too high, or even there is a network of carbides, the plasticity of the Alloy tap decreases, the tendency for quenching distortion cracking increases, and the brittleness of the cutting edge increases, making it easy to break and reducing the service life of the Alloy tap.

3) Before quenching, combined tap and drill should be preheated to reduce temperature differences, minimize thermal stress, and reduce the tendency for distortion in metric thread tap. Especially for W18Cr4V high-speed steel, due to the high quenching heating temperature, if a cold Alloy tap is directly heated in a high-temperature salt bath furnace up to 1280 ℃, the heating speed will cause significant thermal stress and increase the tendency for distortion cracking. Therefore, metric thread tap should be preheated before quenching and heating to reduce temperature differences and thermal stress.