Abstract: A brake drum which can improve the drag strength, strength and rigidity in the diametrical direction, joint strength, and heat radiating ability, that is, a brake drum which is used for a drum brake, wherein the drum has a plurality of the projections at the outer circumferential surface, the plurality of the projections are formed at the outer circumferential surface as a whole when casting a brake drum, and at least part of the projections have thin-waisted shapes. A height of the projections is 0.3 to 5.0 mm, while the number of projections is 5 to 100/cm2. The brake drum is produced by centrifugal casting.

Abstract: A support member with excellent contact with the member to which the support member is attached, that is, a metal support member which supports a shaft directly or through a bearing and which has a plurality of the projections at its outer circumferential surface, wherein the plurality of the projections are formed at the outer circumferential surface as a whole at the time of casting of the support member and wherein at least part of the projections have thin-waisted shapes or a plastic support member which supports a shaft directly or through a bearing and which has a plurality of the projections at its outer circumferential surface, wherein the plurality of the projections are formed at the outer circumferential surface as a whole at the time of molding of the support member and wherein at least part of the projections have thin-waisted shapes.