| 摘要 |
<p>A lead-in type interference fit pipeline external thread (10), it is able to achieve its seal while non-use of packing, in which the effective thread is a cone-shape pipe thread, at least two complete variation convex thread (11) is in full-length of said effective thread, the middle diameter of said variation convex thread (11) is amount of pre-interference fit more than that of its corresponding rules thread (12), the tooth side (100) of said variation convex thread (11) is a convex arc. The invention also involves the manufacturing method and manufacturing device of a lead-in type interference fit pipeline external thread (10), and a lead-in type interference fit pipe thread pair pipe fitting.</p> |
