Study on Factors Influencing the Relationship Between Torque and Clamp Force of Screws

This article selects typical screws and conducts experimental research on the relationship between torque and clamp force using the torque/clamp force testing method. It analyzes the primary failure modes of screws in the torsional tension state, which include failure of the tightening structure (or deformation of the tightening tool), screw fracture or yield, and spring washer failure. Based on this experiment, the distribution proportions of various failure modes are provided. Simultaneously, the influence of screw specifications, tightening position during installation, and typical thread sealant usage on torque coefficient was analyzed, and application suggestions were given to support the assembly scheme design of threaded fasteners.