Side Rails and Their Mounting in Blanking Dies

Side rails control the strip material’s feed direction inside the die. Closed dies use two side rails; semi-open dies use a single side rail. Side rail thicknesses are determined based on whether the die has stops or a side gauge. The side rail thicknesses and mounting used in blanking dies are shown in the figure below.

Side rail thicknesses and mounting in blanking dies (above)

In dies with a side gauge, one of the side rails also serves as a stop. The portion of the side rail that acts as a stop, at the die’s entry mouth, is reduced by the side gauge’s cutting allowance. In dies with stops, no shape modification is made to either side rail. The figure below shows a semi-open die with a single side rail and its mounting.

Semi-open die with a single side rail (above)

If a side rail needs to be used in open dies, the side rails are made in the form of a plate or a stop.

In open dies, the plate or stop type side rail thicknesses used to keep the strip material’s feed direction from shifting must not exceed 3/4 of the strip material’s thickness.

In closed dies with stops, the stop and side rail heights are given in the table below.