Types of Steel Rolling Mill Machine(Two-high/Four-high/Six-high .Mar 20, 2017 . Four -high rolling mills, which has a quick change roll system, can be equipped with roll bend and shape control and can be put in tandem, two to seven stands, instead of reversing mill. Six-high rolling mills, which are similar to four-high rolling mills, also allows for substantial roll shape, depending upon.four high mill rkjain,four high mill rkjain,Modernization of Four-high Heavy-plate Mill Back-up Rolls - SchaefflerSMS group , Germany. Modernization of Four-high Heavy-plate Mill. Back-up Rolls. SMS group offers metallurgical plant and rolling mill technology from one source. The group's plants, machines, services and process know-how are used in the steel, aluminum and other non-ferrous metal industry worldwide.