In order to meet automotive industry’s demand, the weight reduction of car, stronger steel parts should be developed. But, hydrogen delayed fracture, called HDF, occurs drastically in high strength steels over tensile strength of 1.2 GPa. HDF phenomenon is a big obstacle for developing high strength steel, and especially for the wire rod steels for fasteners, such as bolts in car engine. It is the biggest problem to solve because it is directly related to car safety. Several approaches to overcome HDF phenomenon, such as new alloy design and redesigned heat treatment processes, has been tried. Through the approaches, a new steel for 1.4 GPa grade bolts with excellent resistance in HDF was developed.