1.1 This specification covers carbon steel plates, forging quality, intended for forging, quenching-and-tempering, and similar applications in which uniformity of composition and freedom from injurious imperfections are important.

1.2 The plates are available in six grades, or chemical compositions.

1.3 When the steel is to be welded, it is presupposed that a welding procedure suitable for the grade of steel and intended use or service will be utilized. See Appendix X 3 of Specification A 6/A 6M for information on weldability.

1.4 The values stated in either inch-pound or SI units are to be regarded as standard. Within the text, 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 sytems may result in nonconformance with the specification.