Gray iron
（重定向自Grey cast iron）
![Micrograph of grey cast iron.](/Images/godic/202501/16/Gusseisen_mit_Lamellengraphit5806.jpg")
Gray iron, or grey cast iron, is a type of cast iron that has a graphitic microstructure. It is named after the gray color of the fracture it forms, which is due to the presence of graphite. It is the most common cast iron and the most widely used cast material based on weight.