FAQ

Q. Why is graphite suitable for high temperature applications?
A. Graphite has exceptionally high vaporization point of over 3,000°C. Graphite does not liquefy, and stays in a solid state until the temperature reaches its vaporization point. Moreover, mechanical strength of graphite increases as temperature rises. Strength is doubled whcn temperature rises to 2,500°C. These unique characters are some of the reasons which makes graphite as a favorite choice for high temperature applications.

Q. At what temperature does graphite start to oxidize?
A. Temperature oxidation of graphite depends on its surrounding atmosphere. When it is used under inert atmosphere as a nitrogen gas, it will not oxidize until 2,500°C. Although graphite begins to oxidize at 450°C under air.

Q. What's happen when graphite oxidizes?
A. When graphite oxidizes, it will wear and weaken. This will considerably shorten life of graphite. Preventing oxidation is the key to lengthening life of graphite products.

Q. What is the common high temperature application of graphite?
A. Continuous casting dies is one of the common applications. Graphite has exceptionally high thermal conductivity and low thermal expansion which gives quick cooling of molten alloy and high thermal shock resistance. This makes graphite suitable for use as continuous casing dies.

Q. Why is graphite used for EDM?
A. The most commonly used material for EDM electrode is copper. However, graphite is another favorite for EDM electrode. Compared to copper, graphite is much lighter and much easier to machine due to its lower density and hardness. Graphite electrode can be machined precisely compared to copper because it will not deform by friction heat generated during machining.

By controlling the density and porosity through its manufacturing process, graphite can be produced to provide a varied lineup from roughing to finishing grades.

Q. How to choose an equivalent EDM grade?
A. If the user wish to use a graphite grade other than what you are currently using, it is advised that you contact Schunk General Carbon Ltd./Schunk General Carbon (Panyu) Co., Ltd. SGC/SCC will choose an equivalent grade for you.