Why is my punch broken?
• S/D diameter ratio is not correct.
• The material to be punched is not straight but tilted in the die-plate.
• When punching the punch or material is suddenly moved.
• If the wiper is damaged or not properly adjusted in height, the material can become jammed during retraction
of the punch.
• The stripper is too far away from the punch so the thin metal sheet bulges during stripping.
In this case, the punch breaks into sheets on the cutting edge. Therefore we recommend, where appropriate,
using a special hold-down device or providing with the stripper with a bridge.
How high is the punching force?
• For operation conditions please refer to the table.
• Observe the power range of the particular device.
For other materials which are not specified you can calculate the approximate punching force with the following
formula:
F = 3,14 ⋅ x D ⋅ x S ⋅ x R
D = Diameter of the hole to be punched in mm
S = Thickness of the material to be punched in mm
R = Shear strength in N/mm²
F = Punching force in N
Example: W = 3,14 x D16 mm x S16 mm x 300 N/mm² (S233) = F = 241 kN = ca: 24,1 t
With this formula the approximate punching force can be calculated depending on the hole diameter, the thickness
of the material and the shear strength of the material.
For material with higher shear strength we advise:
When punching thicker material with smaller punch diameters, the height of the hold-down device in particular must
be observed in order to prevent jamming or the punch from breaking.
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