kovuusluokkia

Kovuusluokkia is a Finnish term used to describe categories that express the hardness of a material, specifically the material’s resistance to permanent deformation, scratching, or indentation on its surface. It is a way to classify how hard a material appears under certain test conditions.

Hardness is not a single property but a set of related measures. The most familiar hardness scales include the Mohs scale, which is qualitative and used mainly for minerals, and quantitative indentation tests such as Vickers, Knoop, Rockwell, Brinell, and Shore hardness. Each scale uses different indenters, loads, and calculation methods, producing numbers that are not directly interchangeable between scales without appropriate conversions.

Hardness is influenced by a material’s composition, microstructure, heat treatment, and surface finish. For metals, increasing hardness often results from alloying, grain refinement, or work hardening, and it can correlate with wear resistance and strength, though it is not a direct measure of toughness or ductility. Coatings and surface treatments are common ways to modify hardness at the surface without changing the bulk material.

Tests to determine hardness follow standardized procedures, applying a specific load with a defined indenter and measuring the resulting impression. The measured value, expressed in units such as HV, HRC, HB, or SH, depends on the method used. Because different scales are not directly comparable, comparisons of hardness should be made within the same test method and under similar conditions.

Kovuusluokkia is used in materials selection, manufacturing quality control, and engineering analyses to assess suitability for wear-heavy or load-bearing applications.