This specification covers hot-wrought and cold-finished quenched and tempered alloy steel bars. The steel materials shall be melt processed by using open-heart, basic oxygen, or electric furnace and shall conform to the austenitic grain size requirement. Tension tests shall be performed wherein the steel specimens shall conform to the required values of yield strength, tensile strength, and elongation.

1.1 This specification covers hot-wrought and cold-finished quenched and tempered alloy steel bars.

1.2 Hot-wrought bars are available in three strength level classes designated BB, BC, and BD, and cold-finished bars in two strength level classes designated BB and BC. The bars are available in the conditions specified in 4.4 subject to the size limitations shown.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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.