astm a269 حرفه ای مورد استفاده در سیستم های اگزوز
A269 Standard Specification for Seamless and Welded Austenitic … 1.2 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 and …