Fastening member

Claim 1

A fastening member for securing an element on a shaft, which fastening member can be placed without radial play between the external cylindrical surface of the shaft and an interior cylindrical surface of a groove coaxial with said shaft and formed in the element, wherein said fastening member comprises a frusto-conical, metallic, permanently deformable annulus of a material harder than the material constituting the element and shaft and of a predetermined limited elasticity, said annulus having a plurality of recesses on its inner and outer peripheral surfaces to define spaced teeth each having a single edge parallel to the geometrical axis of the annulus and with the parallel edges on the inner periphery being formed by a series of intersecting arcuate cutout portions which define said recesses on the inner periphery whereby said teeth anchor themselves radially in the respective cylindrical surfaces of the element and the shaft when the fastening member is placed in use between said cylindrical surfaces and after the fastening member has been subjected to a sufficient temporary axial pressure to permanently deform and thereby flatten it, so as to secure the element both against rotation and against axial movement relative to the shaft.