Six track grooves formed in a spherical inner peripheral surface of an outer joint member are each formed into an arc shape having a curvature center at a joint center. The track grooves are inclined in a circumferential direction of the outer joint member with respect to a joint axial line, and are adjacent to each other in the circumferential direction with their inclination directions opposite to each other. Six track grooves formed in a spherical outer peripheral surface of an inner joint member are formed so as to be mirror-image symmetrical with the track grooves paired therewith of the outer joint member with respect to a joint center plane at an operating angle of 0°. An inclination angle of each of the track grooves of the outer joint member with respect to the joint axial line is set to 8° or more and 16° or less.