Machine Effects on Formed Section

The capability of any given machine with regard to height or depth of the section is measured mainly by the vertical distance available between spindles.  This, together with the distance from the centerline of the bottom spindle to the top of the machine base and the horizontal center distance between roll stands, establishes the maximum roll diameter.

Let us look at the roll contour of the last roll stage for a simple channel as on Figure #8 and note it relation to the other parts of the machine.  In addition to the restrictions just mentioned, there must be clearance between the outside diameter of the bottom roll flange and the top roll spacer, as well as clearance between the edge of the section and the top roll spacer.  Note also the bottom roll flange diameter includes a lead-in or bell-mouthed contour to aid in threading from one pass to another.