Standard Specification for Quenched and Tempered Carbon and Alloy Steel Forgings for Pressure Vessel Components

1.1 This specification covers requirements for quenched and tempered carbon and alloy steel forgings for pressure vessel components.

1.2 All grades are considered weldable under proper conditions. Welding technique is of fundamental importance, and it is presupposed that welding procedure and inspection will be in accordance with approved methods for the grade of material used.

Note 1-Grades 1 and 1A have different chemistries but the same mechanical requirements. Note 2-Designations have been changed as follows: Current Formerly Grade 1 Grade 1A Grade 1C Grade 2 Class 1 Grade 2 Class 2 Grade 3 Class 1 Grade 3 Class 2 Grade 4N Class 1 Grade 4N Class 2 Grade 4N Class 3 Grade 5 Class 1 Grade 5 Class 2 Grade 11 Class 4 Grade 22 Class 3 Grade 22 Class 4 Grade 22 Class 5 Grade 22V Grade 3V Class 1 Class 1A Class 4 Class 2 Class 2A Class 3 Class 3A Class 7 Class 7A Class 7B Class 8 Class 8A Class 11C Class 22B Class 22C Class 22D Class 22V Class 3V

1.3 The values stated in either inch-pound units or SI (metric) units are to be regarded separately as the standard. Within the text and tables, the SI units are shown in brackets. 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.

1.4 Unless the order specifies the applicable "M" specification designation, the material shall be furnished to the inch-pound units.