| 摘要 |
<p>A method is disclosed of externally and internally upsetting the end of a steel tube to provide a thicker wall for welding to a tool joint and for providing an internal tapered section having a projected length (Miu) along the longitudinal axis of the tube that substantially exceeds today's API standard upset. The method includes three upsetting steps, one pressing step, and one reheating step after the first two steps of the method.</p> |
