Hardness of dislocations, a particular metal's hardness can be controlled. Although seemingly counter-intuitive, as the density of dislocations increases, there are more intersections created and consequently more anchor points. Similarly, as more interstitial atoms are added, more pinning points that impede the movements of dislocations are formed. As a result, the more anchor points added, the harder the material will become. Hardness Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood). Macroscopic hardness is generally characterized by strong intermolecular bonds, but
Leeb rebound hardness test resulting in a greater value 1000×"v/v". A magnetic impact body permits the velocity to be deduced from the voltage induced by the body as it moves through the measuring coil. The quotient 1000×v/v is quoted in the Leeb rebound hardness unit HL. While in the traditional static tests the test force is applied uniformly with increasing magnitude, dynamic testing methods apply an instantaneous load. A test takes a mere 2 seconds and, using the standard probe D, leaves an indentation of just ~0.5 mm in diameter on steel or steel casting with a Leeb hardness of 600 HLD. By comparison,