Shear Angle Calculator
Determine the shear (rake) angle needed on a punch or die to reduce peak tonnage and quiet the press.
Using this calculator responsibly
The Shear Angle calculator is an engineering aid for checking a shop-floor estimate before a setup, quote, or process review. Enter values in the units shown, confirm material properties against the applicable specification, and keep a record of the assumptions used. Calculator output does not override machine capacity, tooling limits, part requirements, or a qualified engineer's approval.
Before using a result in production, repeat the calculation with the extreme values allowed by the print or process window. Check that the selected material, thickness, geometry, and safety factor reflect the actual job. If a result approaches a press, die, fastener, or machine limit, stop and verify it with the equipment manufacturer or responsible engineer.
Inputs and results
Read every field label before entering data and avoid mixing inch and metric values. A useful result should be traceable to the job number, revision, material certification, and machine or tooling record. Treat warnings, invalid ranges, and unusual outputs as reasons to inspect the inputs rather than as values to work around.
Grinding a shear (rake) angle onto the punch or die staggers the moment of cut so the whole perimeter is not sheared at once. This spreads the force over more of the stroke, lowering peak tonnage and softening snap-through.
A shear height of roughly one stock thickness is common. More shear lowers tonnage further but distorts the part, so it is balanced against part flatness.
Formula: Peak force ≈ Full force × Thickness / (Thickness + Shear height)
Worked example
- A flat cut needs 20 tons. Grinding shear equal to the stock thickness (shear height ≈ thickness) roughly halves the peak.
- Result: about 10–12 tons peak instead of 20, easing the press and reducing snap-through.