The hard alloy screw is made of high-alloy alloy powder metallurgy steel containing W, Mo, Cr, V, Si, Co, etc. The material is vacuum quenched and tempered at high temperature or low temperature, and the metallographic structure is tempered martensite. Carbide composition. The screw has high strength, surface hardness and corrosion resistance and certain toughness. It is suitable for wear and corrosion resistant screws. It is widely used in PC, PE, PA, PS, PMMA, ABS, PVC, PSU, POM, plastic wood. , aluminum plastic, transparent plastic and other injection molding.