螺纹连接件占汽车结构中所有连接件的70～80％。目前在汽车修理企业中,车辆大修时,螺钉、螺栓和螺帽的拧出及拧入工作量占拆装总工作量的25～64％。这些数据说明了螺纹连接件实现拆装机械化的必要性。螺纹连接件装配时所需的扭矩为: Threaded connections account for 70 to 80% of all connections in the vehicle’s construction. Currently in the auto repair business, when the vehicle overhaul, screw, bolt and nut screwing out and screwing workload accounted for 25 to 64% of the total workload disassembly. These data illustrate the need for threaded connections to disassemble mechanization. The torque required for the threaded connection assembly is: