In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation, such as an indentation (over an area)...

The Mohs scale (/moʊz/ MOHZ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the...

benefits. It can pose critical problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and...

The Brinell hardness test (pronounced /brəˈnɛl/) measures the indentation hardness of materials. It determines hardness through the scale of penetration...

The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd as an alternative to the Brinell method to measure...

The Rockwell hardness test is a hardness test based on indentation hardness of a material. The Rockwell test measures the depth of penetration of an indenter...

The Janka hardness test (English: /ˈdʒæŋkə/; German: [ˈjaŋka]), created by Austrian-born American researcher Gabriel Janka (1864–1932), measures the resistance...

engineering and metallurgy, hot hardness or red hardness (when a metal glows a dull red from the heat) corresponds to hardness of a material at high temperatures...

Hardness scales may refer to: Scratch hardness The Mohs scale of mineral hardness The Vickers hardness test The Brinell scale The Janka hardness test The...

Carbonate hardness, is a measure of the water hardness caused by the presence of carbonate (CO2− 3) and bicarbonate (HCO− 3) anions. Carbonate hardness is usually...

hardness of approximation is a field that studies the algorithmic complexity of finding near-optimal solutions to optimization problems. Hardness of...

The Shore durometer is a device for measuring the hardness of a material, typically of polymers. Higher numbers on the scale indicate a greater resistance...

were then fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied. This method of manufacture, which...

it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used...

The Knoop hardness test /kəˈnuːp/ is a microhardness test – a test for mechanical hardness used particularly for very brittle materials or thin sheets...

In computational complexity theory, a computational problem H is called NP-hard if, for every problem L which can be solved in non-deterministic polynomial-time...

Scratch hardness refers to the hardness of a material in terms of resistance to scratches and abrasion by a harder material forcefully drawn over its...

Tablet hardness testing is a laboratory technique used by the pharmaceutical industry to determine the breaking point and structural integrity of a tablet...

In computational complexity theory, a computational hardness assumption is the hypothesis that a particular problem cannot be solved efficiently (where...

moissanite is useful for commercial and industrial applications due to its hardness, optical properties and thermal conductivity. The mineral moissanite was...

Vickers Hardness, Rockwell Hardness, Superficial Hardness, Knoop Hardness, Scleroscope Hardness, and Leeb Hardness" (2019) Hardness Conversion Table – Brinell...

Hardness can vary by several hundred percent depending on the pretreatment, see e.g. Iron#Mechanical properties and Angelo Basile; Fausto Gallucci (2011)...

The Erection Hardness Score (EHS) is a single-item Likert scale used to assess the subjective hardness of the penis as reported by the patient. It ranges...

The Barcol hardness test characterizes the indentation hardness of materials through the depth of penetration of an indentor, loaded on a material sample...

Tempering is usually performed after hardening, to reduce some of the excess hardness, and is done by heating the metal to some temperature below the critical...

of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison. Fine-grained white or lightly...

Indentation hardness tests are used in mechanical engineering to determine the hardness of a material to deformation. Several such tests exist, wherein...

A roll hardness tester is a device to measure the roll hardness, hardness profile and hardness variation of paper rolls. In the preparation phase, the...

The Leeb Rebound Hardness Test (LRHT) invented by Swiss company Proceq SA is one of the four most used methods for testing metal hardness. This portable...

The Kampfpanzer Leopard, subsequently Leopard 1 following the introduction of the successive Leopard 2, is a main battle tank designed by Porsche and manufactured...