The mill doesn't use as many work rolls per ton as we thought. It also doesn't need as many bearings and shocks as a tandem mill. SDI added a second shape roll to the second stand. The mill had all its automatic controls only on the first stand, which also serves as the last stand for both passes. We added a shape roll at the end of the first pass and tied that into what would be the second and third stand.
Sheet passes between both stands twice for a total of four reductions.
The mill regularly rolls sheet down to 0.014 inch, although the company has shipped cold-rolled as thin as 0.011 inch. The mill probably can roll as thin as 0.010 inch, but the coils would collapse on themselves because of the tension. To prevent collapse, SDI would need a 20-inch mandrel. Strip cleanliness is an issue at SDI's cold mill. Conventional tandem mills can reduce the oil in the solution used on the strip from 4 percent to 1 percent at the last stand to obtain a cleaner surface with less oil.