| 摘要 |
<p>A draw tool (15) for grooving the inner wall of tubing (17) in which a tool body has longitudinally extending teeth on the surface thereof wherein the teeth are comprised of an approach portion (30) in which the teeth are shaped to define grooves (27) of decreasing cross-sectional area from an inlet to an outlet and a bearing portion (31) where the teeth define grooves of increasing cross-sectional area from an inlet to an outlet.</p> |
