The clamp diaphragm couplings are divided to single diaphragm coupling and double diaphragm coupling. Disc coupling has the features of anti-oil and anti-corrosion. Keyway is optional on request. Disc coupling is used in machine tools, stepping servo system and screw spindle drive. ROUNDSS Flexible couplings provide multiple types: Spider, Diaphragm, Expansion Bushing, Wall-Bellows, Helical, Metal plate spring, Parallel, Fiber glass, and Odham. Most of them have clamp style and screw style, some are also divided into single and double.