蟹吃牛

xièchīniú ㄒㄧㄝˋ ㄔ ㄋㄧㄡˊ

    • to machine a large part on a small machine tool

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
a crab devouring an ox
Meaning
A trade figure of speech for machining a large part on a small machine tool, like a tiny creature tackling a giant. It is used in engineering workshops.

Sources