This specification covers high-yield, quenched, and tempered alloy steel plates for use in welded bridges and other structures. Plates shall be subjected to heat treatment to conform to the tensile and hardness requirements for thickness, tensile strength, yield strength, elongation, reduction of area, and Brinell hardness. Heat and product analysis shall conform to the chemical requirements for carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, vanadium, titanium, zirconium, copper, boron, and columbium. Conformance to required mechanical properties shall be determined by tension and hardness tests.

1.1 This specification covers quenched and tempered alloy steel plates of structural quality in thicknesses of 6 in. [150 mm] and under intended primarily for use in welded structures and other non-welded structures.

Note 1: All grades are not available in a maximum thickness of 6 in. [150 mm]. See Table 1 for thicknesses available in each grade.

1.2 If 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 X3 of Specification A6/A6M for information on weldability.

1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.