BETHLEHEM HOT-ROLLED SHEET XF SERIES alloys B50XF, B60XF, B70XF and B80XF are high strength low alloy steels. The numbers in the alloy designations refer to minimum yield strengths. The steels are made using ladle desulfurization which virtually eliminates harmful stringer type inclusions. The steels were developed for parts that are difficult to form using conventional high strength low alloy steels. This datasheet provides information on composition, microstructure, hardness, tensile properties, and bend strength as well as deformation, and fatigue. It also includes information on forming and machining. Filing Code: SA-383. Producer or source: Bethlehem Steel Corporation. Originally published August 1981, Bethlehem B50XF thru B80XF.