noun
zigzag rasp
A specialized woodworking or metalworking file with a zigzag cutting pattern. The term is technical and not commonly encountered in everyday conversation.
職人は雁木鑢で金属の表面を削った。
The craftsman filed the metal surface with a zigzag rasp.
General term for a file or rasp; 雁木鑢 specifies a zigzag pattern.
Compound of 雁木 (がんぎ, 'zigzag') and 鑢 (やすり, 'file, rasp'). The exact historical derivation is uncertain, but the name describes the tool's distinctive cutting pattern.