... .Third party inspection acceptable Gaphitized petroleum coke for steel, foundry and casting Stable quality Carburizer for special steel, ductile iron High carbon, low sulphur ... Stable quality; Used as carburizer for special steel and ductile iron; High carbon, low sulphur; Quick delivery ... .5-5mm, 1-5mm, 3-8mm, ect. Graphitized Petroleum Coke for Steel, Foudry and Casting