The main mineral components of granite include pyroxene, plagioclase, a little olivine, biotie and trace magnetite. It is precise in structure with black luster and through hundreds of millions years aging, it is of uniform texture, nice stableness, high intensity and rigidity, and can maintain a high precision under heavy weight. So granite is applicable to the works of industrial production and laboratory measurement.

The Jingda granite series instruments are made from well selected JINAN black granite stone,and the precision is in line with the standards of advanced countries. Grade "0",grade "00" and grade "000" are valid.We have standard size in stock.and for special size we can make according to your requirements.

 granite square is used for testing the perpendicularity and parallelism of the workpieces or tools.

Please send us inquiry for quotations ,we will offer you very competitive prices with high quality .Hope this will be a nice start of our long business cooperation.