1.1 This specification covers two kinds of rolls used in machinery for producing corrugated paperboard. Rolls are fabricated of forged bodies and trunnions. The trunnions may be bolted or shrink assembled on one or both ends of the body. A seal weld may be made at the body/trunnion interface. Roll shells are made of carbon/manganese, or low alloy steel as hereinafter described, and are heat treated prior to assembly. Pressure rolls are surface hardened. Provision is made in supplementary requirement S1 for the optional surface hardening of corrugating rolls.

1.2 Corrugating and pressure rolls made to this specification shall not exceed 18 in. [455 mm] in inside diameter. The wall thickness of the roll body shall not be less than 1/12 of the inside diameter or 1 in. [25 mm], whichever is greater, but shall not exceed 3 in. [75 mm]. The wall thickness of the corrugating roll is measured at the bottom of the corrugations in the location of the trunnion fit. The maximum operating temperature of the roll is 425°F [225°C] and the maximum allowable working pressure is 250 psi [1.70 MPa]. The minimum design temperature shall be 40°F [4°C]. The maximum stresses on the roll bodies and the trunnions from the combined internal and external loading are limited to 15 000 psi [103.4 MPa] for the trunnions, 18 750 psi [129 MPa] for the Class 2 pressure roll bodies, and 20 000 psi [138 MPa] for Class 1A, 1B, or 5 pressure roll or corrugating roll bodies in Grades 1 or 2.

1.3 Referring to Table 1, material to Classes 1 A, 1 B, or 5 shall be used for the manufacture of corrugating or pressure roll shells, and Class 2 shall be used only for pressure roll shells. Trunnions shall be made from forgings in either Class 3 or Class 4.

1.4 The values stated in either inch-pound units or SI [metric] units are to be regarded separately as standards. Within the text and tables, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independent of the other. Combining values from the two systems may result in nonconformance with the specification.

1.5 Unless the order specifies the applicable "M" specification designation, the material shall be furnished to the inch-pound units.

1.6 Except as specifically required in this standard, all of the provisions of Specification A788 apply.