The hardness test measures the resistance of a material to an indenter or cutting tool. The indenter is usually a ball, pyramid, or cone made of a material much harder than that being tested. A load is applied by slowly pressing the indenter at right angles to the surface being tested for a given period of time. An empirical hardness number may be calculated from knowledge of the load and the cross-sectional area or depth of the impression.
Tests are never taken near the edge of a sample nor any closer to an existing impression than three times the diameter of that impression. The thickness of the specimen should be at least ten and one-half times the depth of the impression.
Tests are never taken near the edge of a sample nor any closer to an existing impression than three times the diameter of that impression. The thickness of the specimen should be at least ten and one-half times the depth of the impression.
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