In a state where the axes of an inner race (20) and an outer race (30) are inclined with respect to each other, the maximum value of a clearance between the ball-fitting-direction rearward side edge portion of the second inner race raceway (22) of the inner race (20) and the ball-fitting-direction rearward side edge portion of the second outer race raceway (32) of the outer race (30) is larger than the diameter of the respective balls belonging to the second ball row. Also, the maximum value of a clearance between the ball-fitting-direction forward side edge portion of the second inner race raceway (22) of the inner race (20) and the second outer race raceway (32) edge portion on the upper side peripheral surface (33) of the outer race (30) is smaller than the diameter of the respective balls belonging to the second ball row.