Abstract: A cross shaft member has four shaft portions arranged in a generally cross-shape around an outer periphery of a body portion thereof, and a recessed portion is formed in the body portion, and has a depth in a direction perpendicular to a plane in which axes of the four shaft portions lie. Four ridge-like thickened portions are formed in the recessed portion, and are equally spaced from one another, and extend diagonally with respect to the axes of the shaft portions in the plane.