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Calculator
Press brake tonnage calculator
Estimate the force needed to air-bend sheet metal on a press brake. Enter the tensile strength, thickness, bend length and the V-die opening.
How it works
For air bending, the force grows with the tensile strength, with the square of the thickness and with the bend length, and falls as the die opening gets wider. A common rule is a die opening of about six to eight times the sheet thickness.
F (kN) = 1.42 × Rm × t² × L / (1000 × V)
Example
Mild steel with 400 N/mm², 3 mm thick, a 1000 mm bend and a 24 mm die opening needs about 213 kN, which is roughly 22 tonnes.
This is an estimate for air bending. Bottoming and coining need much more force. Choose a press brake with a margin above the result and check the tooling limits.
Hydraulic presses →
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