PURPOSE: To obtain a pattern permitting repeated use, enable secure fitting of product pattern to runner part pattern, and reduce the number of processes, by affixing the head part and metal core of runner part, coating the surface with wax, and constituting an assembled pattern.

CONSTITUTION: Light metal head part, runner part cores 1, 2 are secured with screw part 2a and nut 3 to constitute a securely bonded core assembly 4. A slurry flow preventive plate 5 is inserted in it, and a handle 6 is screwed into a screw hole 1b. A groove part 2c is formed in the product pattern mounting corresponding face 2b of the core 2. Setting the assembly 4 in vertical position, it is dipped in a wax bath up to the plate 5 to form a wax layer 8, so that the assemly pattern 14 may be formed securely with a small amount of wax. A stopper 9 is fitted to a wax well 12c of a runner part pattern 12 placed in horizontal position, and wax of lower melting point than the coat layer 6 is injected. Before solidification thereof, a product pattern 7 is placed promptly, so that a tree pattern 15 is constituted.