A crescent or adjustable wrench, nicknamed for its second career as a hammer. The joke also carries a judgment: an adjustable wrench rounds nuts more readily than a proper box end or socket, so a shop full of them is a shop that does not care about its fasteners. Its real virtue is filling odd sizes when nothing else fits.
Heard on the job
Use the box end, not the adjustable hammer, you're already rounding the corners on that nut.
Also heard as
- crescent wrench
- adjustable
- shifter