noun
hand processing; manufacturing by hand
Refers to processing, finishing, or manufacturing done manually rather than by machine. Common in industrial, craft, and food contexts.
この部品は手加工で仕上げられています。
This part is finished by hand processing.
手加工の工程には熟練が必要だ。
The hand-processing step requires skill.
Compound of 手 (hand) and 加工 (processing). The exact historical derivation is uncertain, but the meaning is transparent from its components.