Granite rail Granite rail is used in CMM, drilling & milling machines for PC Board, Laser machines and CNC as a guideway with Grade00 of DIN876 / GB / JIS. Physical Property of Jinan Black Granite: Specific Gravity: 3.03 g/cm3 Shore Hardness: > 70Hs-80Hs Tensile strength: 211Kg/cm2.
