... corrosion and proof pressure, and are suit for Petrochemical Industry. ASTM A312 is a Standard Specification for Seamless, Welded, and Heavily Cold Worked ... 3.5-5.5% Nickel, 15--16% Chromium)304(approx 7.8-9% Nickel, 17-19% Chromium) 316L(approx 10-12 ... and Gas Industry and Liquird Delivery.6) Surface: 180#, 400#, 600# , 800#, 180# Hairline, 240# Hairline.7) Tolerance: Outer Diameter: +/-0.2mm ...