Press force for press brake operation
The bending force needed in a press brake is influenced by several factors, including material properties, plate thickness, bend length, tooling, and the specific bending method. Adjusting these parameters allows you to modify the required bending force.
To estimate the force needed during bending, consider not only the bend length, plate thickness, die width, and tensile strength, but also the changing moment arm throughout the bending process. The peak load is typically reached at a bend opening angle of 120°, assuming normal friction (no lubrication).
Trial tests are always recommended.
The bending force can also be estimated mathematically.
P = Bend force, metric tons
t = Plate thickness, mm
W = Die width, mm
b = Bend length, mm
Rm = Tensile strength, MPa
Rd = Die entry radius, mm
Rp = Punch radius, mm
If required, you can adjust the following parameters:
- Increasing the die width will reduce the required press force.
- Decreasing the punch radius will also lower the necessary press force.
SSAB have developed BendCalc, which, among other features, calculates the required press force based on friction conditions.
Below is some calculated bending forces needed to bend some SSAB grades
Bending to 90 degrees according to recommendations longitunal to rolling direction as press force per bending length [kN/m].
The information in this report is only applicable to SSAB’s products and should not be applied to any other products than original SSAB products.
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