Abstract: A solid wire of precious metal, such as gold, is drawn through a die which has a groove forming element disposed in a drawing channel located between the inlet and outlet of the die. The hollow wire exiting the die has an eccentric longitudinal open groove extending axially along the wire and embraced by a pair of tapered arms or cusps. The solid portion of the hollow wire is provided with a thick wall portion that is particularly adapted for forming diamond cut facets.
Abstract: A solid wire of precious metal, such as gold, is drawn through a die which has a groove forming element disposed in a drawing channel located between the inlet and outlet of the die. The hollow wire exiting the die has an eccentric longitudinal open groove extending axially along the wire and embraced by a pair of tapered arms or cusps. The solid portion of the hollow wire is provided with a thick wall portion that is particularly adapted for forming diamond cut facets.
Abstract: A rope chain is made from hollow rectangular links having a trapezoidal cross section. The wider parallel surface of the trapezoid is the outer periphery of the shaped link and is the primary surface of the finished rope chain. The narrower parallel surface of the trapezoidal shape, having a channel which forms a longitudinal seam running around the inside of the link, is an inside surface of the finished rope chain and is not visible in a finished chain. The other two sides of the trapezoid converge in symmetrical relationship to the parallel surfaces, and include an angle that approximately equals 360.degree. divided by the number of links required to form a single cycle of links in a double helix, as viewed in an end view of the rope chain. Adjacent links abut, planar surface to planar surface, and form a close fitting circle with a smooth external surface for the rope chain.