Work out punching force instantly with clear inputs, formula shown and shareable results.
Punching shears a cylindrical surface whose area is the hole perimeter times the material thickness, so force is pi x d x t x shear strength. Stripping the punch back out of the hole takes a further 5-10 percent, which the press and stripper plate must also supply.
Punching force
F = pi x d x t x shear strength
Stripping force
F strip = about 0.07 x punching force
F = pi x d x t x shear strength. Punching shears a cylindrical surface whose area is the hole perimeter times the material thickness, so force is pi x d x t x shear strength.
Below a diameter-to-thickness ratio of about one, the punch is loaded in compression beyond its buckling strength and breaks. Thicker material needs proportionally larger holes.
This calculator takes 3 inputs: Hole diameter, Material thickness, Material shear strength. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.