Method for producing brake disc, mold for producing brake disc, and brake disc

A method for producing a brake disc comprising a coupling part having a centered through-hole, a friction part on the periphery of the coupling part, and a wall part connecting the coupling part and the friction part, including: producing a mold in which the coupling part, the wall part, and the friction part are integrally formed, wherein a gap prevents molten metal from overflowing between the wall part and the coupling part, interface is formed on the periphery of the coupling part, an overflow is provided outside the wall part opposite the gap; a first injection process of injecting a first material to form the friction part; and a second injection process of injecting a second material to form the coupling part, a mold for producing the brake disc, and the brake disc.