ASTM A269 Seamless and Welded Austenitic Stainless Steel Tubing for General Service ASTM A269 covers grades of nominal-wall thickness, stainless steel tubing for general corrosion-resisting and low- or high-temperature service. The tubing sizes and thicknesses usually furnished to this specification are 1/4 in.(6.4 mm) in inside diameter and larger and 0.020 in.(0.51 mm) in nominal wall-thickness…