ASTM A192 / A192M Standard Specification
Scope. 1. This specification covers minimum-wall-thickness, seamless carbon steel boiler and superheater tubes for high-pressure service. 2. The tubing sizes and thicknesses usually furnished to this specification are 1/2 in. to 7 in. [12.7 to 177.8 mm] outside diameter and 0.085 to 1.00 in. [2.2 to 25.4 mm], inclusive, in minimum wall thickness.