Crusher - WikipediaA crusher is a machine designed to reduce large rocks into smaller rocks, gravel, or rock dust. . In industry, crushers are machines which use a metal surface to break or compress materials into small fractional chunks or denser masses.jaw crusher user,Jaw Crusher Working Principle - Mineral Processing / MetallurgyFeb 23, 2016 . A sectional view of the single-toggle type of jaw crusher is shown below. In one respect, the working principle and application of this machine is.