Duplex mills have one common base and drive. They can form both edges of narrow or wide products leaving the center flat. The minimum strip width depend on how close the opposing rolls can be pushed together, and the maximum widths usually depend on how far the two mills can be moved from each other. The width of the formed products can be changed quickly by adjusting one or both sides of the duplex mill in or out. Duplex mills either have one side fixed and other one adjustable, or both sides adjustable. Adjustment of a side is usually accomplished by placing all stands on one plate, witch, with proper guides, can be moved in and out, thus changing the gap between the two cantilevered mills. With duplex roll forming mills, it is very easy to change one dimension of product...