| 摘要 |
A self-tapping fastener and method of manufacture wherein said fastener is provided with a unique tapping section, in addition to a driving head and an intermediate threaded portion of generally conventional design. The tapping section is defined by a plurality of interrupted thread turns of an asymmetrical configuration. Each turn includes a pair of diametrically opposed lobe portions, with a pair of opposed side portions disposed intermediate said lobes. One said side portion is defined by a complete absence or void of material provided by a gap of controlled dimensions, while the other is provided by a thread form of an incomplete or under-filled configuration. The fastener of the invention is fabricated by rolling a specially designed blank between a pair of standard thread rolling dies. |
