An object of the present invention is to provide a thread fixing device which forms a through hole and has excellent assemblability of a support member for closing the through hole. A skirt portion (7) is provided with a through hole (9), and a supporting member (10) for closing the through hole (9) and supporting a thread stopper (20). An insertion port 19 through which the support member 10 can be inserted is formed in the front surface 6a of the rear flange 6, and the support member 10 can slide and move in a direction opposite to the through hole 9 and the support member 10 in the radial direction. Guide restriction portions (41, 42, 43) for restricting movement are formed. The through hole 9 is formed by cutting out in a substantially C-shape when viewed from the radial direction, and the circumferential width on the insertion port 19 side is formed larger than the circumferential width on the rear edge side of the through hole 9. . The outer shape of the support member 10 is formed corresponding to the through hole 9 when viewed from the radial direction. The outer surface of the support member 10 is a concave surface 15 that is recessed inward in the radial direction, and the concave surface 15 extends to the front end of the support member 10. [Selection diagram] FIG.【課題】本発明は、本貫通孔を形成する一方で、その貫通孔を閉塞する支持部材の組み付け性が優れた糸止め装置を提供することを課題とする。【解決手段】スカート部７に貫通孔９を設け、貫通孔９を閉塞し糸止め部材２０を支持する支持部材１０を備える。後フランジ６の前面６ａには、支持部材１０を挿入可能な挿入口１９が形成され、貫通孔９と支持部材１０との対向部に、支持部材１０のスライド移動を可能、かつ、径方向の移動を規制する案内規制部（４１，４２，４３）が形成される。貫通孔９は、径方向から視て略Ｃ字状に切り欠いて形成され、挿入口１９側の周方向の幅が貫通孔９の後縁部側の周方向の幅よりも広く形成される。支持部材１０の外形は、径方向から視て貫通孔９に対応して形成されている。支持部材１０の外面は、径方向の内側へ凹む凹面１５であり、凹面１５は、支持部材１０の前端まで続いている。【選択図】図３
