TWI701396B

A brake disc provided with: an annular body portion; a sliding portion protruding from the body portion toward one side in an axial direction of the brake disc, and including an annular sliding surface at an end portion on the one side; and a plurality of fins protruding from the body portion toward another side in the axial direction. The plurality of fins include a plurality of fastening fins having a through-hole for inserting a fastening member, and a plurality of locking fins including a key groove. A contact surface that contacts a rotating member that rotates integrally with the axle is provided around the key groove at the end portion on the other end side of the locking fins. In a radius direction of the brake disc, the distance between the center of the brake disc and the center of the through-hole is greater than the distance between the center of the brake disc and the center of the contact surface.