Referring to FIG. 10, the method 1000 for manufacturing the side member (e.g., the side member 200 of FIG. 4) may include an operation 1010 of forming an outer metal part (e.g., the first metal part 210 of FIGS. 8A and 8B), an operation 1020 of coupling an inner metal part (e.g., the second metal part 220 of FIGS. 8A and 8B) and the outer metal part, an operation 1030 of forming a recess (e.g., the recess 240 of FIGS. 7A and 8B) on contact surfaces (e.g., the first coupling area 271 of FIGS. 8A and 8B), an operation 1040 of forming adhesive layers (e.g., the adhesive layer 260 of FIGS. 7A and 8B) on the outer metal part and the inner metal part, an operation 1050 of forming a polymer part (e.g., the second portion 232 of FIGS. 8A and 8B), and an operation 1050 of machining the side member.
In an embodiment, the operation 1010 of forming the outer metal part may include an operation of bending rod-shaped metal base materials (e.g., first metal base materials 1111 of FIGS. 11A-11E).
