Commonly used unit of hardness is
Answers
Answer:
The Rockwell Hardness test is a hardness measurement based on the net increase in depth of impression as a load is applied. Hardness numbers have no units and are commonly given in the R, L, M, E and K scales. The higher the number in each of the scales means the harder the material.
1.The SI unit of hardness is N/mm². The unit Pascal is thus used for hardness as well but hardness must not be confused with pressure.
2.The commonly used units for hardness measurement are: Brinell Hardness Number (HB) Vickers hardness number (HV) Rockwell hardness number (HRA, HRB, HRC, etc)
Explanation:
1.Hardness is the measure of a material’s resistance to localised permanent deformation. Permanent deformation is also called plastic deformation.
2.While elastic deformation means that a material changes its shape only during the application of force, a resulting plastic deformation means that the material will not return to its original shape.
3.The Rockwell hardness tester utilizes either a steel ball or a conical diamond known as a brale and indicates hardness by determining the depth of penetration of the indenter under a known load.