China's use of black and features: (1) has a good decorative performance, applicable in public places and outdoor decor. (2) has excellent processing performance: sawing, cutting, grinding, drilling and carving. Its processing accuracy of 0.5μm or less, the luminosity of 1600 or more. (3) wear resistance, and 5-10 times higher than cast iron. (4) thermal expansion coefficient is small, easy to distort, and indium steel similar, very slightly affected by temperature. (5) an elastic modulus higher than that of cast iron. (6) rigidity, large internal damping, 15 times bigger than steel. Can shock, shock absorption. (7) Chinese black brittle, damaged after only a partial loss, does not affect the overall flatness. Chemical properties (8) Chinese black stable, easy to weathering, to acid, alkali erosion and corrosive gases, proportional to their chemical nature and silica content, the service life of up to 200 years