SHAFT COMPONENT

Provided is a shaft component exhibiting excellent static torsional strength and torsional fatigue strength. Thus, a shaft component having a chemical composition satisfying formula (1) and containingas essential elements, in mass%, C in the amount of 0.35-0.70%, Si in the amount of 0.01-0.40%, Mn in the amount of 0.5-2.6%, P in the amount of 0.050% or less, S in the amount of 0.005-0.020%, Al inthe amount of 0.010-0.050%, N in the amount of 0.005-0.025%, and O in the amount of 0.003% or less, and also containing optionally selected elements, with Fe and impurities constituting the remainderthereof, wherein: one or more holes are present in the outer-circumferential surface thereof; the volume (R1) by percentage of retained austenite at a depth of 2mm from the outer-circumferential surface is 4-20%; and given that the volume by percentage of retained austenite at a depth of 2mm from the outer-circumferential surface in the axial direction of the holes and a depth of 20 mu m from thesurface of the holes is R2,