Mohs scale of mineral hardness finding the hardest material that the given material can scratch, or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on the Mohs scale would fall between 4 and 5. "Scratching" a material for the purposes of the Mohs scale means creating non-elastic dislocations visible to the naked eye. Frequently, materials that are lower on the Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. While these microscopic dislocations are permanent and sometimes detrimental to the harder material's structural
Roll hardness tester important parameters when deciding whether a paper roll is good or bad. A roll that is wound too softly can go out of round when handled. A roll that is wound too hard, on the other hand, can crack during transportation. These variations are difficult to detect. Above all, it is typically the variation in hardness across a given roll that relates most directly to such converting issues with soft edges being perhaps the biggest contributor. Roll hardness tester A roll hardness tester is a device to measure the roll hardness, hardness profile and hardness variation of paper rolls. In