How to calculate the blade gap of the shearing machine

Blade gap is the distance between the upper and lower blade of the shear as they pass each other during the shearing process. The gap of the blades is the key point to produce a quality cutting and keep the shearing machine working in order.

Figure 1  Blade gap

Collision and shear force should be avoided between upper and lower blades, and a certain gap should be left. However, the gap must be reasonable, because too large gap to turn over the metal sheets. Moreover, it will also make the sheet section rough and cause the section bending and burrs. Therefore, reasonable clearance has impact on the quality of the incision and the dimensional accuracy of the workpiece. The size of gap is decided along with the property of material thickeness and material itself. If it is thicker, the resisting shear strength of the material will be taller and the gap will be bigger as well. The blade clearance is not standardized across all cuts though, it must be readjusted to accommodate for new cuts if needed.

Figure 2  Blade gap table

Improper blade clearance will have an impact on power consumption and terminate the cuts correspondingly. The quality of cuts and edge quality will be reduced if cutting clearance is too large. For the plate shearing to be as efficient as possible, the blade clearance must remain at the optimal adjustment. This step is the biggest key point to provide a quality cutting. Burr elimination and turn over is accomplished by keeping a proper adjustment of the machine blade gap. Adjusting the gap to adapt to the cutting of various places will produce significant results.