| 摘要 |
PCT No. PCT/SE82/00293 Sec. 371 Date May 25, 1983 Sec. 102(e) Date May 25, 1983 PCT Filed Sep. 23, 1982 PCT Pub. No. WO83/01097 PCT Pub. Date Mar. 31, 1983.Nail-type fastener, comprising an elongated shank (1) with a head at one end, and a point at the other end. The nail shank has three symmetrically placed, longitudinal grooves (4) separated by longitudinal ridges (8) with a cross-sectionally arcuate outer side (9). The grooves have flat, concave or cross-sectionally V-shaped bottom surfaces (27;17;7) and usually side flank surfaces (5) arranged obliquely thereto which connect to the bottom surface via individual corners (6) of small radius of curvature. The cross-sectional shape selected provides a nail with high flexural rigidity and high pull grip with comparatively low weight. The fastener or nail is produced starting from a cross-sectionally circular nail wire stock which is profiled in two coldrolling steps. In the first step, the nail wire passes through a first roller trio, the section rollers of which roll cross-sectionally arcuate guide grooves into the nail wire stock. In the second step, the nail wire passes through a second roller trio, the rollers of which engage the guide grooves centrally thereto and produced a deepening of these grooves into deep grooves. The head is then upset on one end of the shank, and a point is made at the other end of the shank, as the finished nail is thereby separated.
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