This standard specifies the classification, code, marking, basic parameters and main dimensions, technical requirements, inspection rules, signs, packaging and storage of core-type elastic couplings (hereinafter referred to as couplings). This standard is applicable to the transmission shaft system connecting two coaxial shafts, and has the performance of compensating the relative offset of the two shafts and general vibration reduction. The working temperature is -20℃~+70℃; the transmission nominal torque is 6.3Nm~8000N.m.