1.1 This specification covers grades of nominal-wall-thickness, austenitic alloy steel tubing for general corrosion-resisting and low- or high-temperature service, having a specified minimum chromium content of less than 10.50%.

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.

1.4 Some steels covered by this specification, especially the high silicon containing steels, because of their particular alloy content and specialized properties, may require special care in their fabrication and welding. Specific procedures are of fundamental importance, and it is presupposed that all parameters will be in accordance with approved methods capable of producing the desired properties in the finished fabrication.

1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. Unless the order specifies the applicable "M" specification designation (SI units), the material shall be furnished in inch-pound units.