A269/A269M Standard Specification for Seamless and
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 heavier. 1.3 Mechanical property requirements do not apply to tubing smaller than 1 / 8 in. [3.2 mm] in inside diameter or 0.015 in. [0.38 mm] in thickness.