This standard specifies the types and parameters, technical requirements, test methods, and inspection rules of JM I type, JM IJ type, JMⅡ type, and JMⅡJ type diaphragm coupling. Logo, packaging and storage, etc. This standard is applicable to couplings that connect two coaxial transmission shaft systems, have certain performance in compensating the relative offset of the two axes, have a working environment temperature of -20~+250℃, and transmit a nominal torque of 25~10000000N·m.