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. 2019
Examples from the Web for air-hardening
Historical Examples of air-hardening
This alloy, because hardened simply in air, was called “air-hardening” or “self-hardening.”Inventors at Work