POWER-TRANSMISSION SHAFT AND ASSEMBLY

摘要

Provided is a power-transmission shaft that can use narrow-diameter raw materials and can reduce costs by minimizing materials costs and lathing costs. Also provided is an assembly using such a power-transmission shaft. The provided power-transmission shaft has: an end-section male spline (31); an engagement widened section (37) that restricts push-down in the axial direction when the male spline (31) is fitted into a female spline (45) on another member; and a boot groove (33) for mounting a boot. Letting the external diameter of the engagement widened section (37) be D2, the maximum external diameter of the male spline (45) be D1, and the external diameter of a boot mounting section (32) provided with the boot groove (33) be D4, D2 is less than D1 and D2 is equal to D4. The external diameter of the engagement widened section (37) and the boot mounting section (32) is the diameter of the raw shaft material.