Figure 4-138.  General brake overview including radius shims.  Figure 4-139.  Adjust clamping pressure with the clamping pressure  nut. Figure 4-140.  Brake nose gap adjustment with piece of material  same thickness as part to be formed.  Clamping pressure adjustment nut Brake nose gap adjustment knob Pull forward to clamp (no sponginess felt when evenly set on BOTH sides) Note: Bending leaf counterbalance omitted for clarity Limiting stop Nut to adjust clamping pressure Lifting nut Radius shims Material to be bent Step 3: Adjusting the Nose Gap Adjust the nose gap by turning the large brake nose gap  adjustment knobs at the rear of the upper jaw to achieve  its proper alignment.  [Figure 4-140]  The perfect setting  is obtained when the bending leaf is held up to the angle  of the finished bend and there is one material thickness  between the bending leaf and the nose radius piece. Using  a piece of material the thickness of the part to be bent as a  feeler gauge can help achieve a high degree of accuracy.  [Figures 4-140  and  4-141]  It is essential this nose gap be  perfect, even across the length of the part to be bent. Check  by clamping two test strips between the bed and the clamp 3  inches from each end of the brake.  [Figure 4-142]  Bend 90°  [Figure 4-143] , remove test strips, and place one on top of  4-71