Method for the manufacture of self-locking nipples

A method for the manufacture of self-locking nipples comprising:

• providing a semi-finished product for a nipple having a predetermined axis (X), with a head that is enlarged with respect to a shank,
• providing a plurality of blind holes in the head running along the axis (X), the plurality of blind holes comprising a first blind hole and further blind holes arranged in a ring around the axis (X) at a distance therefrom which is less than the diameter of the first blind hole, the further blind holes being of shallower depth than the first blind hole,
• injecting a fluid resin into the plurality of blind holes and solidifying the injected resin so as to obtain a corresponding insert nested therein,
• making a second axial hole in the semi-finished product at least partly intersecting the insert, the second axial hole being designed to receive a threaded extremity of a spoke,
• further comprising forming a thread in the second hole in a portion which is not in contact with the insert after the fluid resin is injected into the blind holes so as to form a threaded portion in the second hole;
• wherein the plurality of blind holes are positioned such that part of the cross-section of the blind holes subsequently intersects the second axial hole when the latter is made in the semi-finished product;
• wherein the insert comprises a stop member engaging in a corresponding seat in the blind holes;
• and
• wherein the seat is produced by the further blind holes.