A downhole tool used in fishing operations to engage on the outside surface of a tube or tool.
在打捞作业中所用的一种井下工具，在打捞时它与管子或工具的外表面接合。
2
Since the mandrel is the most critical thermal deformation operation tool for the retained mandrel pipe mill (MPM) process, its operation efficiency is decisive to steel tube operational cost.
芯棒是限动芯棒连轧钢管机组中最重要的热变形工具，其使用效果决定着钢管生产成本的高低。
3
During induction heat treating of pump tube, quenching machine tool plays a key role to fulfill the required properties.