A securing device which permits the outer end of the hair-spring in a timepiece to be fastened either by gluing or pinning it in place. A U-shaped arm extends radially of the axis of the balance wheel and provides a pair of ears, one for gluing the hair-spring and the other for pinning it. The manufacturer of the watch can thus use the ear for gluing the outer end of the hair-spring, as this method has advantages for production purposes. When the hair-spring is replaced, the watch-repairman can use the other ear for pinning the outer end of the hair-spring without deforming the hair-spring, thereby obtaining the advantages of this method for repair purposes.
