Granite leveling rulers are also known as granite straight ruler,granite leveling rulers are manufactured according to International standard to ensure the high quality.The products are always made into ribbed plate or box-type, our company use the scraping process to improve the precision of the products. Since the products are customized, so the customers can customize the size according to the actual needs.

Therefore, precision black granite leveling  ruler export to foreign countries is popular in all the world.

• Granite paraller ruler are mainly used in testing the flatness and perpendicularity working -surfaces of the parts.
• Precision has 000. 00, 0,  grade

• what is granite ?

We using Jinan black granite stone for  granite series instruments. it is have high quality .Due to the high precision,long duration,good stability and corrosion resistance,they have been more and more used in product inspection of modern industry and scientific areas as mechinary space and scientific researches Physical characteristics,

Specific gravity,2970----3070kg

Compressive strength,245---254N

Coefficient of linear expansion.4.6×10~6°C

Water absorption,0.13%

Shore hardness,more than Hs70