caseharden

[ keys-hahr-dn ]

verb (used with object)

1. Metallurgy. to make the outside surface of (an alloy having an iron base) hard by carburizing and heat treatment, leaving the interior tough and ductile.
2. to harden in spirit so as to render insensible or insensitive to external impressions or influences; make callous.

Word History and Origins

Origin of caseharden¹

First recorded in 1670–80; case ² + harden

Example Sentences

I have a peculiar kind of steel which I cannot harden by fire and water, neither will it caseharden by prussiate of potash.

From Project Gutenberg