Hardness 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 the behavior of solid materials under force is complex; therefore, there are different measurements of hardness: "scratch hardness", "indentation hardness", and "rebound hardness". Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. There are three
Janka, Contai Khejuri I and Khejuri II CD Blocks. It covers an area of 268.47 km with a population of 231,777. Janka, Contai Janka is a village, in Khejuri II CD Block in Contai subdivision of Purba Medinipur district in the state of West Bengal, India. Khejuri police station is located at Janka. The headquarters of Khejuri II CD Block are located at Janka. As per 2011 Census of India Janka had a total population of 2,804 of which 1,452 (52%) were males and 1,352 (48%) were females. Population below 6 years was 347. The total number of literates in Janka was