This specification covers dimensions@ gaging practices@ and gages for internal threads in valves@ fittings (except couplings)@ and flanges for use with line pipe@ casing@ and tubing conforming to API specifications. NOTE: Coupling threads and external threads on valves and fittings are not covered by this specification. They should conform to the requirements specified in the corresponding pipe specification. Nothing contained in this specification is to be construed as granting any right@ by implication or otherwise@ for manufacture@ sale@ or use in connection with any method@ apparatus@ or product covered by letters patent@ nor as insuring anyone against liability for infringement of letters patent.