Granite Squares provide one of the most reliable squareness inspection reference. Work is positioned against the square and sighted for checking squareness of components by comparison method. Granite Squares are also used for checking squareness of measuring axis in Co-ordinate Measuring Machines and geometrical alignment of Machine Tools.
Cast Iron Universal Knee Type Right Angle are widely used for making fixtures as well as for checking squareness and parallelism of surfaces. All machined faces are square and parallel and job can be rotated in different planes that are square with respect to each other.