Granite slab precision reference measurement tools, natural stone material, for instruments, precision tools, machinery parts of the test, is an ideal base. Particularly for high-precision measurements, because of its unique characteristics, leaving the cast iron plate dwarfs. Granite based on the quality of the rock layers underground, after millions of years of natural aging, form extremely stable, do not worry because the conventional temperature and deformation. The rigorous physical testing and selection of granite materials, fine crystalline, hard, compressive strength of 2290-3750 kg / cm, hardness of Ta Mok's hardness 6-7. Extremely resistant to abrasion, acid and alkali, high corrosion resistance, never rust I plant: threaded plug, threaded ring, smooth Cypriot ring, smooth ring gauge, calipers, sine Regulation Mohs gauge, various test rods, cylindrical Square, square box, flat, V-shaped frame, granite slab, flat feet parallel to the regulation, rectangular device, square boxes and other non-scalar gage. Mitsubishi imports of wire walking external processing Tel:. 18632765185 QQ: 1101491384 Website: http://www.hhjmlj.com/