Hardness has been variously defined as a solid materials resistance to abrasion, penetration, scratching, tear or wear. This proves that hardness is not an inherent property of a material rather the result of a defined measurement procedure carried out as part of hardness tests.
The ideal method to arrive at the Hardness Value of a material is to measure the depth/ area of the indentation produced by an indenter of a definite shape when a specific force is applied on it for a specified period. This relationship between hardness and the size of the impression is usually established using three standard test methods, known as the Brinell, Vickers, and Rockwell tests.
Each one of these test methods makes use of a definite scale (which is dependent on the applied load and indenter-shape) for calibration purpose. Thus, the Brinell Hardness Scale gauges the hardness of metals. Similarly, the Rockwell Hardness Scale measures different materials, right from soft bearing metals to carbides and the Vicker's Scale measures the hardness of thin materials.
The Hardness scales have another function - individual scales allow conversions to other scales. Thus, according to the Hardness Conversion Table, a Hardness value of 36 in the Rockwell (Diamond Brale) C Scale is equivalent to the following Hardness Values:
52 in the Rockwell (Diamond Brale) D Scale,
109 in the Rockwell (1/16" Bull) B Scale,
331 in the Brinell Scale (using a 10 m/m Ball) and
354 in the Vickers Scale.
Remember that all these hardness values have been arrived at by using varying weights.
Continue Reading Hardness, Hardness Tests And Hardness Conversion Tables
Proceq manufactures quality nondestructive portable testing instruments for metal hardness, concrete properties and roll hardness tester. Proceq invented the Equotip portable metal hardness tester and the world’s first portable concrete test hammer, the Schmidt concrete test hammer.
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