This standard specifies the type, basic parameters and main dimensions, technical requirements, inspection rules and markings, packaging, storage, etc. of cross-axis universal couplings for straightening machines. The couplings specified in this standard are mainly suitable for roller plate straightening machines, but also for other mechanical equipment. Its rotation diameter is 46~150mm, the nominal torque is 90~6300N·m, and the axis folding angle α≤10°.