MIL-S-23284A, MILITARY SPECIFICATION: STEEL FORGINGS, CARBON AND ALLOY, FOR SHAFTS, SLEEVES, PROPELLER NUTS, COUPLINGS, AND STOCKS (RUDDERS AND DIVING PLANES) (15 JUN 1990)., This specification covers carbon and alloy steel forgings for torsional shafts, including propulsion shafts for ships, sleeves, couplings, propeller nuts, rudder stocks, diving plane stocks, and related parts.