This specification covers double pour, centrifugally cast, abrasion-resistant roll shells for general application. The outer layer is white iron and the inner layer is gray iron and there shall be no gradient of mottled iron these layers. Both the white and the gray irons may be melted by any suitable melting process. The white iron portion of the casting shall be produced by chemistry rather than chilling. A chemical analysis of the white and gray irons shall be taken and the chemical compositions shall be controlled to obtain the required mechanical properties. The white iron (Types I, II, III, and IV) shall conform to the specified Brinell hardness and the gray iron (Class Nos. 20, 25, 30, and 35) shall conform to the specified tensile strength. The minimum thickness of the white iron layer is given. Hardness and tension tests of the cast dual metal shall be performed.

1.1 This specification covers double pour, centrifugally cast, abrasion-resistant roll shells for general application. The outer layer is white iron and the inner layer is gray iron. There shall be no gradient of mottled iron between the white iron and the gray iron.

1.2 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.