Vickers method is based on an optical measurement system, it specifies a range of light loads using a diamond indenter to make an indentation which is measured and converted to a hardness value. It is very useful for testing on a wide type of materials, but test samples must be polished to enable measuring the size of the impressions. A square base pyramid shaped diamond is used for testing in the Vickers scale. Typically loads are very light, ranging from 5gf to 2Kgf, although "Macro" Vickers loads can range up to 50 Kg or more. Micro Vickers hardness methods are used to test on metals, ceramics, and composites - almost any type of material. Since the test indentation is very small in a Vickers test, it is useful for a variety of applications: testing very thin materials like foils or measuring the surface of a part, small parts or small areas, measuring individual microstructures, or measuring the depth of case hardening by sectioning a part and making a series of indentations to describe a profile of the

HRC is most applicable to testing carbon steel after quenching or low tempering, alloy steel, tool steel, die steel, as well as chilled cast iron, titanium alloy and so on. Generally, we apply HRC scale to test materials HRB>100, and HRB scale to test materials HRC<20 avoiding influence caused by glide of indenter.