The General Introduction It is produced in a high temperature electric resistance type furnace from a mixture of quartz sand and petroleum coke. Characteristic 1.good hardness 2. toughness 3.high efficiency 4. durability. 5.heat-resistant property 6.low heat expansion coefficient 7.high heat conductivity coefficient 8.higher strength and toughness 9.high thermal conductivity Size we provide full size is available as per customer's request