Punching Tonnage Formula
The punching tonnage is calculated by using the following formula：
Length of the cut edge (mm) x Material Thickness (mm) x Tensile Strength (kg/mm2)/1000
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Example 1
Rectangle 50 x 10 in 2.0 mm Stainless Steel
Tonnage Required = (50+50+10+10) x (2.0) x (60)/1000
Tonnage Required = 14.4 Tonnes
Example 2
30mm Diameter in 1.5 mm Mild Steel
Tonnage Required = (3.142 x 30) x (1.5) x (40)/1000
Tonnage Required = 5.7 Tonnes
Minimum Hole Diameter
As a general guideline, the following table shows the minimum diameter（mm）of a punched hole with regard to material thickness.
t = Material Thickness
| Material Type | Minimum Hole Diameter |
| Mild Steel | 1.0xt |
| Aluminum | 1.0xt |
| StainlessSteel | 2.0xt |
It is possible to punch smaller hits, please contact the tooling manufacturer for assistance.