| 摘要 |
The disclosed swaging tap has lobes or high points of its thread disposed on a helical spiral twist path of opposite hand to the thread, the angle of the reverse twist path with respect to the tap axis being either identical to the helical angle of the thread or at least materially less than twice the helical angle of the thread, the angle of the thread being by definition the angle between the thread crest and a plane normal to the axis.
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