Keménységi

Keménységi is a term used in Hungarian to describe the property of hardness, or the resistance of a material to scratching, indentation, penetration, or wear. It encompasses how difficult it is to deform a material's surface under applied forces and can be applied across a range of disciplines, including materials science, engineering, and geology. The word is often used in phrases such as keménységi érték (hardness value) or keménységi vizsgálat (hardness test).

Hardness is typically measured using standardized tests and scales. Indentation-based methods, such as Brinell, Vickers, and Rockwell tests, yield numerical hardness values (HB, HV, HRC, etc.) and are commonly used for metals and ceramics. Scratch-based hardness, most famously represented by the Mohs scale, ranks minerals from 1 (talc) to 10 (diamond) according to scratch resistance and is still widely used in mineralogy. Polymer materials often employ Shore hardness scales. Each method has its own principle, scale, and suitability depending on material type and application.

It is important to distinguish hardness from other mechanical properties. A material can be very hard yet brittle, offering high scratch resistance but low toughness. Conversely, a tough material may be softer. Hardness is influenced by composition, microstructure, temperature, and testing conditions, and it is frequently used in material selection, wear resistance assessment, and quality control.

See also: hardness test, Mohs scale, Vickers hardness, Rockwell hardness, Brinell hardness, Shore hardness.