... Ⅲ. Major Structure The major frame is consist of upper roller, lower roller and bracket, major actuator, reversing system, balance system, ... rate: 0.7 of the largest pressure of upper roller. Upper roller is made of alloy steel 42CrMo, after the ... the dissymmetrical rolling.3-3. Support Roller Part Support roller part is consisting of support roller, bearing pedestal, inclined wedge framework, ...