切削

1. Origins, structure, and basic meaning

• Structure: 切削 (せっさく) means machining material by removing it with a tool. 切削して is the operation; 切削中 is the time span during which it is underway.
• Basic usage: 切削して links machining metal to shaping a part, while 切削中 defines when protective glasses must be worn.

2. Common pitfalls and similar expressions

• Machining action and safety period during machining
  • して links the cutting operation to its result; 中 turns the operation into an ongoing time interval. The contexts emphasize machining rather than simple severing such as 切断.