- noting any metal, especially alloy steel, that can be hardened from above its transformation point by cooling in air.
Origin of air-hardening
First recorded in 1905–10
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a process of hardening high-alloy steels by heating and cooling in a current of airCompare oil hardening
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012