| 摘要 |
<p>A drill string member is formed by providing a former (2) and a cylindrical member (1) to be shaped in relationship with the former. Seals (20) are provided between opposing ends of a thick wall cylinder (3) and the cylindrical member, a pressure is applied in the annulus (4) between the cylindrical member and the thick wall cylinder sufficient to deform the cylindrical member against the former. The drill string member thus formed has a constant wall thickness and a non-circular former provides a non-circular drill string member.</p> |
