Description
Kobe Steel’s investigation resulting in the development of new steel wire rod for 80 kfg/mm 2 class non heat-treated bolt, with good ductility, is reported. A review is provided of the quality design, the microstructure and chemical composition of wire rod, and equations used in determining tensile strength of wire rod and bolt size. Extensive testing indicated a superior product for deformability, flow stress of drawn wire, and of the bolts themselves.