PURPOSE: To improve a degree of rigidity ever so high, by molding an end member solidly with a lace body in a way of making an extension part of a core material the central part.

CONSTITUTION: At the side of a lace body 21 nearby an extension part 31 of a core material 30, there is provided with a stepped bolt 40, while a weir member 50 is locked to the core material 30. In order to mold an end member 60, a mold B2 is covered over an end part of the lace body 21 and under this condition, if resin is poured out of an inlet port B3 and injection molding takes place, the form of the end member 60 is made up because a core material insertion groove 22 is blocked up by the weir member 50. Since the extension part 31 of the core material 30 extends as far as a tip end of the end member 60, each end part of the end member 60 and a molding 20 are reinforced.