The Vickers hardness tester uses a square-based diamond pyramid indenter, and the hardness number is equal to the load divided by the product of the lengths of the diagonals of the square impression. Vickers hardness is the most accurate for very hard materials and can be…

The Vickers Diamond Pyramid Hardness tester, which measures the DPH mentioned above, uses an indenter with an included angle of 136° between opposite faces of a pyramid and usually a load of 10, 30, or 50 kilograms-force. The diagonal of the impression is measured optically, and…

The Vickers test was designed primarily for metals. With the Knoop test, however, the hardness of extremely brittle materials including glass and even diamonds can be measured without harming either the indenter or the test piece.