ASME B36 19 Pipe
A 4 inches (100 mm) Schedule 80 pipe has an outside width of 4.500 inches ( 114.30 mm), a divider thickness of 0.337 inches (8.56 mm), giving a drag of 3.826 inches (97.18 mm) Hardened steel types 304 and 304L. Type 304 is the most adaptable and generally utilized hardened steel.