This standard applies to joints of steel pipes used for fluids such as steam, air, gas, water, and oil, as well as nominal pressures of 5K, 1OK, 1OK, thin type, and 16K for use in cast iron pipes, pipe fittings, valves, etc. and 20K cast iron pipe flanges (hereinafter referred to as flanges) with nominal diameters from 1OA to 1500A.