Hardness (solids)

Description

A property of solids that indicates the materials resistance to abrasion and deformation. Various methods are used to characterize hardness, the oldest of which is the Mohs' hardness scale for minerals. The Mohs' scale is based on the ability of a harder mineral to scratch the surface of a softer one. In metallurgy, hardness is measured as the resistance of a material to indentation by another material. The Brinell and Rockwell hardness measurements use either a Steel, Tungsten carbide, or Diamond ball which is pressed onto the testing material with a known load. then the resultant size and depth of the indentation is measured. Other methods, such as Vickers, Tukon, Shore (scleroscope), Knoop, or Eberbach, use a diamond pyramid as the indentor. Durometer hardness is used for materials such as rubber and plastics.

Synonyms and Related Terms

"Härte (Deut.); dureté (Fr.); dureza (Port.)

Sources Checked for Data in Record

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998