A machine part such as a cylinder or a feeding screw of an injection molding machine and the like is produced such that a separating metallic plate is inserted in a mold adapted to mold the cylinder or the feeding screw, thereby providing two molding cavities on both sides of the separating plate, and melted metals adapted to form a main portion and a corrosion and wear resistant portion of the cylinder or feeding screw are poured into the two cavities. In this manner the two kinds of metals poured into the two cavities are metallurgically fused together with the separating plate interposed therebetween.