1964BS 7S 1:1964+A2:2015 Specification for Carbon steel bright bars for machining. (540 MPa; maximum size, 101 mm diameter or minor sectional dimension)
1964BS 7S 1:1964 Specification for aircraft material - Carbon steel bright bars for machining (35/45 tonf/sq in; maximum size, 4 inches diameter or minor sectional dimension)