Alloy Indefinite Chilled is cast iron with fine inter-crystalline graphite evenly distributed throughout the working layer of roll barrel.The sizes, shapes and distributions of graphite and carbide are controlled by the chilling effect and the contents of alloy elements.The addition of alloy elements such as Mg,Ni,Cr,and Mo changes the matrix from pearlite and bainite to martensite. Plus the present of small amount of fine graphite, the performance of spalling resistance, thermal crack resistance and wear resistance were enhanced significantly. The material has small hardness gradient in the working layer of roll barrel and is suitable for intermediate and finishing stands for bar,wire and section mills.