摘要 |
1,122,443. Self-tapping screws. RESEARCH ENG. & MFG. Inc. 8 Feb., 1966, No. 5480/66. Heading B3N. [Also in Division F2] In a combination of a male and female screwthreaded members, the male member, e.g. a self-tapping screw 10, comprises a generally triangular transverse cross-section to provide a thread form having spaced-apart lobes 12, 14, 16, which interfere with the female thread at (44) and (50), Fig. 4, not shown.
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