| 摘要 |
<p>A method and apparatus for producing tubing from hollows or workpieces which are in the form of tubes having greater wall thickness than the finished tubes. The method is carried out upon a mill of the general type known as a McKay rocker. The mandrel is allowed to float in the hollow by being restrained at the rocker crosshead by friction rather than a positive locking device. The rocking is permitted with the mandrel sliding in the crosshead so as to reduce high tensile forces which could otherwise cause mandrel failure.</p> |
