To achieve optimum flatness in 4 and 6 High mills, mill builders have developed increasingly advanced selective cooling systems.

These are needed especially to address the problem of non-symmetrical flatness errors. Stressometer Systems can be integrated with, and control, all existing spot cooling systems, whether simple on/off systems, advanced multi-step or pulse length controlled. ABB can also design and deliver new spot cooling spray bars when upgrading older mills with Stressometer Flatness Control Systems.

In a 4 or 6 High mill a correctly designed and controlled spot cooling system permits higher rolling speeds and higher production as well as several I-units improvement in overall flatness. Keeping the roll in perfect thermal balance with the ABB spot cooling system will provide significant improvements in production.