ABSTRACT
Hardness measurement is a very simple and useful technique to characterize the mechanical properties of materials. It provides an accurate, rapid, and economical way of determining the resistance of materials to plastic deformation, usually by penetration. The hardness of a material is related to its strength, and also to its wear and fatigue resistance. In spite of its importance, hardness is an unusual property in that it is measured in an essentially arbitrary manner. It is not possible to give it a precise de“nition in terms of the fundamental SI units of mass, length, and time. Compared with other methods of measuring the strength of materials, hardness tests are mostly nondestructive in nature. Additionally, hardness measurements do not require any special size and shape of specimens and the testing equipment is simple and is available in almost every laboratory. Further, other mechanical properties, for example, tensile strength, may be estimated from hardness data. Consequently, hardness measurement is an important means of quality control in manufacturing operations.
