Abstract: A bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to an embodiment of the present invention consists of, in mass %, C: 0.32 to 0.39%, Si: 0.15% or less, Mn: 0.40 to 0.65%, P: 0.020% or less, S: 0.020% or less, Cr: 0.85 to 1.25%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.050%, B: 0.0010 to 0.0030%, N: 0.0015 to 0.0080%, O: 0.0015% or less, Mo: 0 to 0.05%, V: 0 to 0.05%, Cu: 0 to 0.50%, Ni: 0 to 0.30%, and Nb: 0 to 0.05%, with the balance being Fe and impurities. The bolt satisfies Formula (1) and Formula (2), and has a tensile strength of 1000 to 1300 MPa and satisfies Formula (3). 4.9?10C+Si+2Mn+Cr+4Mo+5V?6.1??(1) Mn/Cr?0.55??(2) [dissolved Cr]/Cr?0.

Abstract: A bolt is provided that has high strength and excellent hydrogen embrittlement resistance characteristics. A bolt according to an embodiment of the present invention consists of, in mass %, C: 0.32 to 0.39%, Si: 0.15% or less, Mn: 0.40 to 0.65%, P: 0.020% or less, S: 0.020% or less, Cr: 0.85 to 1.25%, Al: 0.005 to 0.060%, Ti: 0.010 to 0.050%, B: 0.0010 to 0.0030%, N: 0.0015 to 0.0080%, 0: 0.0015% or less, Mo: 0 to 0.05%, V: 0 to 0.05%, Cu: 0 to 0.50%, Ni: 0 to 0.30%, and Nb: 0 to 0.05%, with the balance being Fe and impurities. The bolt satisfies Formula (1) and Formula (2), and has a tensile strength of 1000 to 1300 MPa and satisfies Formula (3). 4.9?10C+Si+2Mn+Cr+4Mo+5V?6.1 ??(1) Mn/Cr?0.55 ??(2) [dissolved Cr]/Cr?0.

Abstract: The present invention relates to a metallic, precise columnar member having an outer diameter with high accuracy, wherein the columnar member comprises a plurality of flattened thread ridges having a predetermined outer diameter provided on the surface of a metallic columnar blank in an axial direction. The method of the present invention comprises the steps of using rolling to form a plurality of thread ridges on the surface thereof and using rolling or drawing to make the tops of the thread ridges flat.

Abstract: This invention relates to a bolt comprising a bolt shank formed at an outer peripheral surface thereof with external threads, and a nut formed at an inner peripheral surface thereof with internal threads, comprising a latch means for latching the nut with the bolt shank, which is provided on at least one of the bolt shank and the nut, the nut being separatable from the bolt shank and capable of being screwed onto the bolt shank, wherein the nut is movable relative to the bolt shank in a state of being screwed onto the bolt shank, when a larger torque than a predetermined torque is applied to the nut while the latch means latches the nut with the bolt shank.