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The Janka hardness test (English: / ˈ dʒ æ ŋ k ə /; [1] German:), created by Austrian-born American researcher Gabriel Janka (1864–1932), measures the resistance of a sample of wood to denting and wear. [citation needed] It measures the force required to embed an 11.28-millimeter-diameter (7 ⁄ 16 in) steel ball halfway into a sample of ...
Lignum vitae is hard and durable, and is also the densest wood traded (average dried density: ~79 lb/ft 3 or ~1,260 kg/m 3); [4] it will easily sink in water. On the Janka scale of hardness, which measures hardness of woods, lignum vitae ranks highest of the trade woods, with a Janka hardness of 4,390 lbf (compared with Olneya at 3,260 lbf, [5] African blackwood at 2,940 lbf, hickory at 1,820 ...
Download QR code; Print/export Download as PDF; ... The Vickers hardness test; The Brinell scale; The Janka hardness test; The Rockwell scale; The Durometer scale;
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The invention of the use of Guaiacum for syphilis. The genus is famous as the supplier of lignum vitae, which is the wood of several species in the genus. [citation needed] It is the fourth-hardest variety of wood as measured by the Janka hardness test, requiring a force of 4,500 lb f (20,000 N) to embed a steel ball 0.444 in (1.13 cm) in diameter half that distance into the wood.
Knoop hardness test (HK), for measurement over small areas, widely used to test glass or ceramic material. [8] Janka hardness test, for wood; Meyer hardness test; Rockwell hardness test (HR), principally used in the USA. HRA, HRB and HRC scales are most widely used. [9] Shore hardness test, for polymers, widely used in the rubber industry. [10]
A variety of hardness-testing methods are available, including the Vickers, Brinell, Rockwell, Meyer and Leeb tests. Although it is impossible in many cases to give an exact conversion, it is possible to give an approximate material-specific comparison table for steels .