This SAE Recommended Practice applies to flywheels for dry spring-loaded clutches used on internal combustion engines. figure 1 and Tables 1, 2, and 3 report information currently used in the industry. Clutches requiring other dimensions are also manufactured. Dimensions given are primarily for single- plate clutches. Flywheels for two plate clutches have the same dimensions if an adaptor for the intermediate plate and second driven disc is supplied with the clutch. If instead the flywheel is to be extended to adapt the intermediate plate and second driven member, consult the clutch manufacturer for the required J dimensions and drive arrangements for the intermediate plate.