Another purpose of reducing is to make tapered material. As an example, knives are made from high carbon steel that is heated up red hot and reduced from a thickness of approximately 3/16” to 1/16” by 10” to 48” long.
Why is your golf club shaft tapered? Why is a knife thick at the handle and thin at the end? Why are aircraft parts made with one side thicker than the other? Such tapered rolling is becoming more common. Shapes need to be high strength and flexible to keep the overall weight to a minimum. Tapered rolling is done with mechanical or hydraulic screwdowns. The work rolls are adjusted automatically with an encoder from the rotation of the work rolls. Almost any taper, form, or irregular shape can be rolled on this type of special rolling mill. Tapered rolling mills can be a 2-high or 4-high configuration, depending upon the separating force and other factors to determine the best possible design.