Translation guide
A mechanical spring made by coiling wire. In Japanese, the most common term is コイルばね, but other expressions exist depending on context.
coil spring
The learner wants to refer to a coil spring in a general mechanical or everyday context.
I'm learning about the design of coil springs.
Direct loanword from English. Used in some technical or automotive contexts, but コイルばね is more natural.
The coil spring needs to be replaced.