This specification covers high-strength low-alloy structural steel plate used for tubular structures and poles. This steel has atmospheric corrosion resistance so it can be used bare or unpainted for many applications. The materials shall be made by fine grain practice, normal furnishing in the as-rolled condition, and normalizing heat treatment. Chemical requirements shall be obtained by heat analysis. Mechanical requirements shall be done by tension test and Charpy V-notch impact test.

1.1 This specification covers high-strength low-alloy steel plate intended for use in tubular structures and poles or in other suitable applications. Two grades, 60 and 65, may be provided as-rolled, normalized or quenched and tempered as required to meet the specified mechanical requirements.

1.2 The atmospheric corrosion resistance of this steel in most environments is substantially better than that of carbon structural steels with or without copper addition (see Note 1). When properly exposed to the atmosphere, this steel can be used bare (unpainted) for many applications.

Note 1: For methods of estimating the atmospheric corrosion resistance of low-alloy steels, see Guide G101.

1.3 When the steel is to be welded, it is presupposed that welding procedures 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 Supplementary requirements in accordance with Specification A6/A6M are available, but shall apply only when specified by the purchaser at time of ordering.

1.5 The values stated in either inch-pound units 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 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.

1.6 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.