Stripper Pressure Calculator
Calculate the force required to strip the material off the punches so you can size stripper springs correctly.
Using this calculator responsibly
The Stripper Pressure 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.
After the cut, the stock clings to the punches and must be stripped off. Stripping force is a fraction of the cutting force — light for thin soft stock, higher for thick or sticky material.
A common planning rule is 10–20% of the cutting force. The spring system must deliver this force at the top of the stroke. (The Punch Force calculator reports the same 10–20% band; size springs toward the upper end.)
Formula: Stripping force ≈ 10% to 20% of Cutting force
Worked example
- If the cutting force is 18,000 lb, stripping force ≈ 1,800–3,600 lb.
- Size the stripper springs for the upper end so they strip reliably at full punch withdrawal.