Rigid core for forming tire

A rigid core for forming a tire which comprises an annular core body provided in its outer surface with a tire molding surface region for forming a green tire and which is for subject the green tire to vulcanization molding between a vulcanization mold and the core body by being put into the vulcanization mold together with the green tire, characterized in that

• the core body comprises a plurality of circumferentially divided core segments,
• both circumferential end surfaces of each of the core segments are used as mating surfaces, and the mating surfaces adjacent to each other in the circumferential direction are abutted against each other to form the core body, and
• at least one of the mating surfaces adjacent to each other in the circumferential direction is formed as a stepped mating surface comprising a bordering surface region extending along an outer circumferential edge of the mating surface, and a recessed surface region surrounded by the bordering surface region and recessed in a step shape from the bordering surface region so that only the bordering surface region contacts with the adjacent mating surface.