Selection of screw nut materials: heat treatment process of 45 steel screw and 40Cr steel screw quenching and tempering. Quenching and tempering is a dual heat treatment of quenching and high-temperature tempering. Its purpose is to make the workpiece have good comprehensive mechanical properties. There are two categories of quenched and tempered steel screws: carbon quenched and tempered steel and alloy quenched and tempered steel. Whether it is carbon steel or alloy steel, the carbon content control is relatively strict. The raw material of the trapezoidal screw is drawn through the mold to the required medium diameter size, and is cold drawn twice to form a surface hardness (0.5 mm deep) of (18°-21°). Trapezoidal screws are adopted to perform standards. Nut materials are traditionally selected: tin bronze 6-6-3 and tin-zinc bronze 5-5-5. Aluminum-tin bronze ZCUA110Fe3 is selected, HRS~1000, with small friction coefficient, no noise and flexible rotation.