1.1 This specification2 covers several grades of minimum-wall-thickness, seamless and welded, carbon and alloy-steel tubes intended for use at low temperatures. Some product sizes may not be available under this specification because heavier wall thicknesses have an adverse affect on low-temperature impact properties.1.2 Supplementary Requirement S1 of an optional nature is provided. This shall apply only when specified by the purchaser. Note 1: For tubing smaller than 1/2 in. [12.7 mm] in outside diameter, the elongation values given for strip specimens in Table 1 shall apply. Mechanical property requirements do not apply to tubing smaller than 1/8 in. [3.2 mm] in outside diameter and with a wall thickness under 0.015 in. [0.4 mm]. (A) For each reduction of 0.01?% carbon below 0.30?%, an increase of 0.05?% manganese above 1.06?% will be permitted to a maximum of 1.35?% manganese.1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard.