non-upset tubing thread

例句：

1. 1. The engineer useda special tool to cut the non-stressed tubing thread.
   工程师使用特殊的工具来切割非紧张型管材螺纹。
2. 2.The new machine is designed to handle non-stressed tubing thread more efficiently.
   这台新机器被设计用来更高效地处理非紧张型管材螺纹。
3. 3.The pipeline was repaired using a non-stressed tubing thread that matched the original design.
   管道被修复，使用的是与原始设计相匹配的非紧张型管材螺纹。