... -1991),MSS-SP-79\ 83\ 95\97 AND BOTH-WELL SPEC.MATERIAL SPEC: ASTM A105, ASTM A182(F304, F304L, F316, F316L, F304H, F316H ... , F317L,F321, F11, F22, F91).SIZE OF RAW MATERIAL: DIA. 19-85MM ROUND BAR.5. MARKING:CARBON AND ALLOY ... STEEL: MARKED BY STAMPING.STAINLESS: MATERIAL,HEAT NO. B16(BELONG TO ANSI B16. 11 PRODUCT),PRESSURE ...