| 摘要 |
<p>The base of the thread groove has a concave and partially circular cross-section over at least part of the groove length and the transition region between the base and groove flanks comprises concave radial regions, the radius for the latter reducing from the front end of the thread towards the rear end, whilst at the same time the groove base radius increases in the same direction. The tops of the thread form a tangent with an imaginary cylinder or cone concentric to the female part.</p> |
