PURPOSE: To enable the hole on the surface of a product to be removed, while the supporting pin of a mold is made unnecessary by a method in which the supporting members made of resin or metal are fitted onto the peripheral surface and the end of a core, and after the core has been kept at the prescribed position in a molding chamber, resin is injected into the molding chamber, whereby a protecting tool is integrally molded around the core.

CONSTITUTION: A plurality of supporting members 3, 4 are fitted to the outer peripheral surface and both ends of an annular core 2. The supporting member 3 is fitted to the core, while the part of said member is inserted into the hole 6 of the core 2, and the supporting member 4 is fitted to the core, while the inserting groove 4a formed at its one end, is fitted onto the end edge of the core 2. These supporting members 3, 4 are molded of the resin which has almost same mechanical strength as that of the synthetic resin molding a protecting tool. When the core 2 is arranged in the molding chamber 10 between the molds 8, 9, the supporting member 4 on the end of the core 2 is brought in contact with upper end lower surface of the molds 8, 9, and the supporting member 3 on the peripheral surface of the core is brought in contact with the outer peripheral surface of the molding chamber 10, whereby the core 2 is kept at prescribed burying position. Next, when resin is injected into the molding chamber 10 from an injecting port 11, the surrounding of the core 2 is filled with resin 5, and the supporting members 3, 4 and the resin 5 become integral, whereby a cylindrical protecting tool 1 is molded.