Graphite is carbon crystal and nonmetal material with the natures of silver gray, soft texture, metal luster, Mohs hardness 1~2, specific gravity 2.2~2.3 and volumetric weight 1.5~1.8 in general.

2.Graphite features very high melting point. It starts to melt at 3000°C in vacuum and evaporates at 3600°C. Strength of most materials decreases under high temperature but, on the contrary, the strength of graphite will increase in double when it is heated to 2000°C. However, graphite's oxidation resistance property is poor and temperature rise may quicken the Oxidation process of graphite.

3.Graphite is noted for excellent thermal and electrical conductivity, which is 4 times that of stainless steel, 2 times that of carbon steel and 100 times that of most nonmetal materials. Of graphite, thermal conductivity is better than that of metals, including steel, iron and lead, but decreases when temperature rises. Unlike metals, when temperature is extremely high, graphite will be of thermal insulation. So, the property of graphite in heat insulation under high temperature is accountable.