ASTM A312 Stainless Steel Pipe Specification Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes ASTM A312 pipe is common use stainless pipe for industries. It covers diameters from 1/8” to 30” and thickness from SCH 10S to SCH 80S. General use material grades are TP304/304L, TP316/316L.