This specification covers structural quality carbon-manganese-silicon steel plates in three tensile strength ranges intended primarily for service at atmospheric temperatures where improved notch toughness is important. If the steel is to be welded, a welding procedure suitable for the grade of steel and intended use or service shall be utilized. The steel shall be made by fine grain practice. Heat and product analysis shall conform to the chemical composition requirements prescribed for carbon, manganese, phosphorus, sulfur, and silicon. The tension test specimen shall conform to the tensile requirements including tensile strength, yield point, and elongation.

1.1 This specification covers structural quality carbon-manganese-silicon steel plates in three tensile strength ranges.

Note 1: This specification was originally intended primarily for construction of storage tanks used at ambient temperatures when improved toughness was needed over that available in semi-killed ingot cast steels.

1.2 Plates covered by this specification are limited to a maximum thickness of 1.5 in. [40 mm].

1.3 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.

1.4 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 are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.5 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.