| 摘要 |
<p>A self-opening diestock which is characterized by the fact that it comprises a rotating operating part which carries the thread-cutting dies that are capable of radial travel and have two grooves in which are accommodated the heads; means for exerting an outward thrust upon the cutting dies; means for restraining the cutting dies, where both said means are embodied onto the operating part; a flange which is capable of axial travel and carries the head of the means for restraining, and a stop piece attrached to the flange, which is capable of axial travel, and upon which the end of the pipe to be threaded rests.</p> |
