Karkaistun

Karkaistun is the genitive singular form of the Finnish adjective karkaistu, meaning hardened or tempered. It is used in Finnish to describe a noun that has undergone a hardening process, most commonly in technical contexts dealing with metals and materials. The form appears when the associated noun is in the genitive case, for example in phrases describing properties or characteristics of the material.

In everyday and technical usage, the more common attributive form karkaistu is used before nominative nouns, as in karkaistu teräs, meaning hardened steel. When the noun is in genitive, the adjective takes the genitive ending, yielding expressions such as karkaistun teräksen kovuus (the hardness of the hardened steel) or karkaistun teräksen lujuus (the strength of the hardened steel). These constructions are typical in specifications, lab reports, and engineering texts.

Origin and related terms: The verb karkaistaa means to harden, typically through a heat treatment or other processing that increases hardness. Related nouns include karkaistus (the hardening process) and karkaistuminen (the act or state of becoming hardened). Finnish technical language often contrasts karkaistu with other material states such as pehmeä (soft) or normaalinen (annealed), depending on the desired properties of the material.

See also: karkaistus, karkaistu teräs, teräslaatu. Notes on usage: Karkaistun is not used as a standalone noun; it functions as a grammatically inflected modifier within noun phrases describing hardened materials.