Outside joint member for constant velocity universal joint and constant velocity universal joint equipped with the same

Abstract

To reduce sensitivity to a delayed fracture and secure fracture strength required for a shank.SOLUTION: There is provided an outside joint member 21 for a constant velocity universal joint including a cup part 22 and a shank 23 extending from the bottom part of the cup part 22 outward in an axial direction, in which a spline 24 is formed on an outer peripheral surface of the shank 23 and a surface hardened layer 30 formed by hardening is provided at least in a formation area of the spline 24. In the surface hardened layer 30, a surface layer area of 0.2 mm deep or less from the surface of the shank 23 is formed in a low hardness layer 31 with Vickers hardness (HV) of 400-550, and a deep layer area of 1.5 mm deep or more from the surface is formed in a high hardness layer of HV 650-800 formed by hardening.SELECTED DRAWING: Figure 2

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