B.S. 1640 : Part 1 : 1962 : Specification for steel butt - welding pipe fittings for the petroleum industry : Part 1. wrought carbon and febric alloy steel fittings
- London British Standard Institution
STD418
B.S. 1640 : Part 1 : 1962
STD418
B.S. 1640 : Part 1 : 1962