1.1 This specification covers five grades of high-strength low-alloy structural steel shapes, plates, sheet piling, and bars. Grades 42 [290], 50 [345], and 55 [380] are intended for riveted, bolted, or welded structures. Grades 60 [415] and 65 [450] a This specifiation covers the standard requirements for Grades 42 [290], 50 [345], 55 [380], 60 [415], and 65 [450] of high-strength low-alloy columbium-vanadium structural steel shapes, plates, sheet piling, and bars for applications in bolted, welded,