| 摘要 |
1,204,642. Forging nuts; screw cutting nut. G. A. TINNERMAN. 9 April, 1969 [22 April, 1968], No. 18282/69. Headings B3H and B3N. [Also in Division F2] A female fastener 1 has an aperture for receiving a shank, the wall of said aperture comprising a cylindrical segment 3 which intersects with an end face 8 of the fastener in a helical edge 10, and a helical rib 23 axially and radially inward of said edge formed by displaced material of said cylindrical segment. In a method of making a female fastener a surface 8 is formed by displacing material around one end of an aperture which receives a shank to form a helical edge with the wall of said aperture, Fig. 3, and displacing the material of the wall of the aperture to form a helical rib axially and radially inwardly of said edge, Fig. 4. The fastener has two cylindrical segments separated by grooves 4 so that material displaced by the rib from a shank is easily removed. Ribs may be provided at both ends of the aperture of the fastener.
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