Hardness tests

qualitative ordinal scale characterizing scratch resistance of various minerals

In materials science, hardness (antonym: softness) is a measure of the resistance to plastic deformation, such as an indentation (over an area) or a scratch (linear), induced mechanically either by pressing or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured i

The way to measure the hardness of a material is with a special tool called an indenter, which is pressed into the material and the larger the cavity, the harder the material.

hardness test

Rockwell hardness scale based on indentation hardness of a material with a 120° diamond spheroconical under 150 kgf

micro-hardening test

Nanoindentation, also called instrumented indentation testing, is a variety of indentation hardness tests applied to small volumes. Indentation is perhaps the most commonly applied means of testing the mechanical properties of materials. The nanoindentation technique was developed in the mid-1970s to measure the hardness of small volumes of material.

test to measure the resistance of a sample of wood to denting and wear

hardness testing machine

European impact protection standard

test to measure the strength of a gel or gelatin

hardness scale in mineralogy

any measure of hardness based on indentation resistance

thumb|right|A nanoindenter