case-hardened steel

1. 1.

   steel with a surface that is much harder than the interior metal

   Broadersteel

Questions about case-hardened steel

What does case-hardened steel mean?

case-hardened steel means "steel with a surface that is much harder than the interior metal".

Is case-hardened steel a common word?

case-hardened steel is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.