METHOD OF MANUFACTURING CORE PRODUCT, AND CORE PRODUCT

A method of manufacturing a core product includes injecting molten resin into a resin injection portion provided in a core body so as to extend in a longitudinal direction of the core body, and forming a core product by welding the core body. A buffer region is set between the resin injection portion and a periphery of the core body in a lateral direction of the core body. The core product is formed by welding the core body so that a weld bead formed on the core body is prohibited from reaching the buffer region, and so that the weld bead is spaced apart from the resin injection portion in the lateral direction of the core body.