| 摘要 |
1,116,799. Self-tapping screws. P. L. ROBERTSON MFG. CO. Ltd. 17 Nov., 1965, No. 48878/65. Heading B3N. A self-tapping screw comprises an end portion 3, Figs. 1-3, of square pyramidal, or conical form, having a tapping screw thread 5 thereon, and a machine screw thread 7 connected to screw thread 5, on which a nut (15), Fig. 7 (not shown), can be screwed, after the screw drills and taps a hole in sheet metal members (11), (12). |
