Punching Force Calculator

Inputs

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Sets how the cut perimeter is computed.
Hole / slug diameter. Used for the round shape.
mm
First side of a rectangular punch. Used for the rectangle shape.
mm
Second side of a rectangular punch. Used for the rectangle shape.
mm
Total sheared perimeter of any profile (sum all cut edges). Used for the custom shape.
mm
Stock thickness being sheared.
mm
Material shear strength — commonly estimated at 0.7-0.8 × UTS; mild steel sheet is often taken around 280-350 MPa.
MPa
Force to strip the stock off the punch on the return stroke, as % of punch force. Die-design references quote 10-20% as the usual band.
%

Results

Default result
Edit inputs
Punching force(F)
56,550N
Pass

56.55 kN · 12,710 lbf · 5.77 t

Perimeter × thickness × shear strength — the press requirement.

Also computed

Stripping force8,482N

8.482 kN · 1,907 lbf · 0.865 t

Sizes the stripper springs / plate, not the press.

Cut perimeter(p)62.83mm

Method notes 4 notes
  • Flat-faced punch at full perimeter engagement: F = p·t·τ. Grinding shear (angle) on the punch or die spreads the cut over the stroke and lowers the PEAK force — common practice for big blanks on small presses.
  • Shear strength is a material property you enter — the 0.7-0.8 × UTS estimate is a handbook starting point; the data sheet governs, and work-hardened or high-strength sheet runs higher.
  • Stripping force sizes the stripper (springs or plate); it acts on the return stroke and is not added to the press tonnage for simple tools.
  • Die clearance, slug control, punch tip stress and minimum-hole-vs-thickness limits are die-design territory beyond this screen.

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