face-harden

[ feys-hahr-dn ]
/ ˈfeɪsˌhɑr dn /

verb (used with object)

to harden the surface of (metal), as by chilling or casehardening.

Origin of face-harden

First recorded in 1895–1900

British Dictionary definitions for face-harden

face-harden

verb

(tr) to harden the surface of (steel or iron) by the addition of carbon at high temperature