BOLT, AND STEEL MATERIAL FOR BOLTS

WIPO Patent Application WO/2020/162616

A1

Provided are: a bolt exhibiting excellent delayed fracture resistant properties at a high strength level not less than 1200 MPa but less than 1600 MPa in terms of tensile strength where the possibility of delayed fracture occurring is extremely high; and a bolt steel material serving as a material for said bolt. The bolt has a compositional makeup satisfying formulae (1) and (2), and has a tensile strength not less than 1200 MPa but less than 1600 MPa. (1): 0.48≤Mo/1.4+V<1.10. (2): 0.8