Knoop hardness


Knoop hardness
(HK or KHN)
   a measure of the hardness of a metal introduced by Knoop in 1939. The Knoop test is similar to the Vickers test in that a diamond penetrator is used to indent the sample being tested, but it uses a rhombohedral diamond rather than a pyramidal diamond point. It is similar to the Rockwell test in that the hardness measure is the depth of the penetration rather than its area. The result is measured in kilograms of force per square millimeter but should be stated as an empirical measurement, without units.

Dictionary of units of measurement. 2015.

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  • Knoop hardness — ▪ mineralogy       a measure of the hardness of a material, calculated by measuring the indentation produced by a diamond tip that is pressed onto the surface of a sample. The test was devised in 1939 by F. Knoop and colleagues at the National… …   Universalium

  • Knoop hardness — /nup ˈhadnəs/ (say noohp hahdnuhs) noun microhardness of metal measured by resistance to indentation by a pyramidal diamond indentor. {named after Frederick Knoop, 1878–1943, US instrument maker who devised this means of measuring metal hardness} …   Australian English dictionary

  • knoop hardness — ˈnüp noun Usage: usually capitalized K Etymology: after F. Knoop, 20th century American chemist : the relative hardness of a material (as a metal) that is determined by the depth to which the bluntly pointed diamond pyramid of a special… …   Useful english dictionary

  • Knoop hardness number (HK) — Knoop hardness number (HK). См. Число твердости по Кнупу. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Knoop hardness test — Knoop hardness test. См. Определения твердости по Кнупу. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Knoop hardness test — The Knoop hardness test is a microhardness test a test for mechanical hardness used particularly for very brittle materials or thin sheets, where only a small indentation may be made for testing purposes. A pyramidal diamond point is pressed into …   Wikipedia

  • Knoop hardness number — See under number. * * * a number indicative of the degree of relative hardness of a material, calculated from the load employed and the length of the long axis of the impression made by the rhomboidal pyramid of a diamond pressed into the surface …   Medical dictionary

  • Knoop hardness test — a micro hardness test in which an elongated pyramidical diamond is pressed into the surface …   Mechanics glossary

  • Hardness of prominent abrasive materials — ▪ Table Hardness of prominent abrasive materials abrasive materials hardness Mohs scale (Mohs hardness) Vickers scale (Vickers hardness) Knoop scale (Knoop hardness) Natural abrasives industrial diamond 10 10,000 8,000 corundum 9 2,200 1,600… …   Universalium

  • Knoop-Härteprüfung — Härte ist der mechanische Widerstand, den ein Werkstoff einer mechanischen Einwirkung entgegensetzt. Je nach der Art der Einwirkung unterscheidet man verschiedene Arten von Härte. So ist Härte nicht nur der Widerstand gegen härtere Körper,… …   Deutsch Wikipedia


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