The Yoder Universal Cage Forming System, originated and patented by Yoder, is based on sound mathematics and unique concepts. This method becomes more desirable and essential as the ratio of the pipe outside diameter to wall thickness (i.e., D/t ratio) exceeds 40:1, and up to 100:1 range. More conventional forming methods roll material in discrete steps or passes and employ brute force. The Yoder Cage System forms the strip continuously with smooth transitions and minimum effort. Hence, the material is actually guided through the forming mill with uniform but infinitesimal change of shape in each small increment of pipe travel.
The buckling of strip edges in light wall pipe has been a shortcoming of the conventional pipe mill. This is problem is even more evident now that higher yield strength materials are allowing pipe producers to decrease the wall thicknesses (and pipe weight) further, thus increasing the D/t ratio even more.
