A tool used for smoothing or shaping metal, wood, etc. The word is usually written in kana.
I file down the burrs on the metal with a file.
A coarse file is handy for woodworking.
ultra-fine rasp; ultra-fine file
zigzag rasp
The word is usually written in kana. The kanji form 鑢 is rare and may not be recognized by many readers.
Katakana spelling is sometimes used, especially in technical or tool contexts.
Kanji form is uncommon; most speakers use kana.
The origin is uncertain. The kanji 鑢 is a kokuji (Japanese-made character) combining 金 (metal) and 慮, but the word itself is likely a native Japanese term.