A. Description of granite surface
Adopting high quality “Jinan Qing” natrual mateirial of granite, granite surface plate is manufactured by mechanical processing and manual lapping. It dosen't only own the advantages of black gloss, precise construction,even character, nice stability, high strength and hardness, but also no rust, acid&alkali-proof, no magnetization, type stable, nice abrasion resistance and can keep stable at normal tempreture and heavy.
The main mineral ingredients of granite are pyroxene, anorthose, less olivine, black mica and less magnetite. Aging through hundreds of millions years, the granite can still retain even character, stable, high strength and hardness, and can keep high precision at heave duty. It is suitable for industrial production and measuring works at laboratory.
Proportion：2970-3070kg/m3
Compression strength，245-254kg/mm2
Flexible grinding capacity，1.27-1.47N/mm2
Coefficient of linear expansion，4.6×1－6℃
Water absorption 0.13%
Shore hardness HS， more than 70。
Precision has 000. 00, 0, 1 grade. It is the ideal tool for drawing line and inspection at precision processing company.
