Patent ID: 7163461

Claim:
A cross joint comprising: a cross shaft member comprising: four shafts each comprising a neck portion and a race portion; and shoulder portions between adjacent neck portions; rolling members adapted to rotate on the race portions; and bearing cups fitted to the respective shafts via the rolling members, wherein a round-shaped section of at least one of said shoulder portions has a center of curvature at an outer side of the cross shaft member, wherein the round-shaped section does not include a concave angled corner, wherein the shoulder portions are subjected to roller burnishing for increasing a hardness of each surface of the shoulder portions and for increasing a residual compressive stress immediately below each of said surfaces, and wherein a residual compressive stress at a depth of up to 0.3 mm from each of surface of the shoulder portions subjected to roller burnishing is larger than a residual compressive stress at the deeper portions thereof.