Submitted by György Chityil ... on Fri, 01/19/2018 - 20:57 Hierarchy: NounDescription: {{metallurgy}} The process of imparting greater hardness to the surface of a piece of metal.Ngram: case hardeningNgram Text: case hardeningSource: WiktionaryIssue: 0Wiktionary tag: metallurgyNgram Count: 2