hardness tester

device
      device that indicates the hardness of a material, usually by measuring the effect on its surface of a localized penetration by a standardized rounded or pointed indenter of diamond, carbide, or hard steel.

      Brinell hardness is determined by forcing a hardened steel or carbide ball of known diameter under a known load into a surface and measuring the diameter of the indentation with a microscope. The Brinell hardness number is obtained by dividing the load, in kilograms, by the spherical area of the indentation in square millimetres; this area is a function of the ball diameter and the depth of the indentation.

      The Rockwell hardness tester utilizes either a steel ball or a conical diamond known as a brale and indicates hardness by determining the depth of penetration of the indenter under a known load. This depth is relative to the position under a minor initial load; the corresponding hardness number is indicated on a dial. For hardened steel, Rockwell testers with brale indenters are particularly suitable; they are widely used in metalworking plants.

      The Vickers hardness tester uses a square-based diamond pyramid indenter, and the hardness number is equal to the load divided by the product of the lengths of the diagonals of the square impression. Vickers hardness is the most accurate for very hard materials and can be used on thin sheets.

      The Shore scleroscope measures hardness in terms of the elasticity of the material. A diamond-tipped hammer in a graduated glass tube is allowed to fall from a known height on the specimen to be tested, and the hardness number depends on the height to which the hammer rebounds; the harder the material, the higher the rebound. See also Mohs hardness.

* * *


Universalium. 2010.

Look at other dictionaries:

  • hardness tester — kietmatis statusas T sritis Standartizacija ir metrologija apibrėžtis Medžiagos (metalų ir jų lydinių) kiečio matuoklis. atitikmenys: angl. durometer; hardness tester vok. Durometer, n; Härtemesser, m; Härtemessgerät, n rus. дюрометр, m;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • hardness tester — kietmatis statusas T sritis chemija apibrėžtis Medžiagos kietumo matuoklis. atitikmenys: angl. durometer; hardness tester rus. твердомер …   Chemijos terminų aiškinamasis žodynas

  • hardness tester — Смотри Склерометр …   Энциклопедический словарь по металлургии

  • hardness tester — Смотри Твердомер …   Энциклопедический словарь по металлургии

  • rebound hardness tester — Смотри Склероскоп …   Энциклопедический словарь по металлургии

  • Hardness — This article is about mechanical properties of materials. For other uses, see Hard. Hardness is the measure of how resistant solid matter is to various kinds of permanent shape change when a force is applied. Macroscopic hardness is generally… …   Wikipedia

  • Vickers hardness test — A Vickers hardness tester The Vickers hardness test was developed in 1924 by Smith and Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials.[1] The Vickers test is often easier to use than other… …   Wikipedia

  • Indentation hardness — tests are used to determine the hardness of a material to deformation. Several such tests exist, wherein the examined material is indented until an impression is formed; these tests can be performed on a macroscopic or microscopic scale. When… …   Wikipedia

  • Rockwell scale — The Rockwell scale is a hardness scale based on the indentation hardness of a material. The Rockwell test determines the hardness by measuring the depth of penetration of an indenter under a large load compared to the penetration made by a… …   Wikipedia

  • steel — steellike, adj. /steel/, n. 1. any of various modified forms of iron, artificially produced, having a carbon content less than that of pig iron and more than that of wrought iron, and having qualities of hardness, elasticity, and strength varying …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.