Other steel pipe fittings excluding socket shall be manufactured from steel by any approved process.
6.3.1
Unless otherwise specified by the purchaser, all fittings shall be manufactured with thread connections, complying with the requirements of IS 554. At the request of the purchaser, the manufacturer is permitted to make plain end fittings without screwing as per the dimensions given in the relevant tables. The outside diameter of the plain end fittings match with the outside diameter of tubes in accordance with IS 1239 (Part 1). Outside diameter of the internal threaded fittings shall be same as outside diameter of sockets as per Table 6.