Knoop hardness scale
A hardness scale based on measuring indentations that was developed in 1939 by F. Knoop, a 20th century chemist. The Knoop hardness scale ranges from glass (300-600) to diamond (6000-6500). A Knoop hardness tester drops a pointed diamond indentor onto a material then examines the size and depth of the indentation to determine surface hardness. This test is generally used on brittle materials like ceramics.
Synonyms and Related Terms
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
- Encyclopedia Britannica, http://www.britannica.com Comment: Knoop Hardness." Encyclopædia Britannica. 8 Sept. 2004 .