Gussform

A casting mold includes a cavity formed therein, and a core projecting into the cavity. The core forms a concave portion in a cast product, and it exhibits a thermal expansion coefficient being equivalent to or more than a thermal expansion coefficient exhibited by a molten metal to be charged into the cavity. Hence, the core greatly expands thermally during casting, and it keeps the expanded state during the solidification of the molten metal. Accordingly, the casting mold can prevent the casting defects resulting from the shrinkage cavities from arising in the resulting cast products. All in all, the casting mold can obviate to give the core a tapered configuration, and it can reduce the after-casting machining allowance to be provided in the resulting concave portion.