摘要 |
<p>A method of cold forming a self-attaching female fastener (20) which includes deforming a fastener blank (120) having an annular pilot, (122) an annular flange (128) surrounding the pilot and a groove (132) in the flange having cylindrical walls and annular protrusions (152, 154) on the flange and pilot, then deforming the protrusions toward each other to form an annular re-entrant groove (32) having relatively inclined arcuate walls.</p> |