Press Brake Calculation Tool
Air Bending Tonnage Calculator
Estimate the bending force required for conventional 90° air bending. Enter the material tensile strength, sheet thickness, bending length and V-die opening.
Enter Bending Conditions
Please enter valid values for tensile strength, sheet thickness, bend length and V-die opening.
1 MPa = 1 N/mm²
Material thickness to be bent
Actual length of the bend line
Actual lower die opening used
Recommended V-Die Opening
Approx. 64 mm / Standard V63
Estimated Bending Result
Estimated Required Tonnage
--
tf
Total Bending Force
--
kN
Force Per Meter
--
kN/m
Selected V / t Ratio
--
V/t
Natural Inside Radius
--
mm approx.
Minimum Flange Length
--
mm approx.
Bending Method
90° Air Bending
This result is an engineering estimate for conventional 90° air bending in a V-die.
Verify machine, punch, die and tool holder capacity before production.
Calculation Basis and Scope
The calculated force is based on conventional air bending in a V-die using material tensile strength,
sheet thickness, bending length and die opening.
FkN/m =
Rm × t2 / V ×
(1 + 4t / V)
Total Tonnage =
FkN/m × L / 1000 ÷ 9.80665
Rm = tensile strength in MPa / N/mm²;
t = sheet thickness in mm;
L = bend length in mm;
V = V-die opening in mm.
The approximate natural inside radius is calculated as 16% of the selected V-opening.
The approximate minimum flange length is calculated as 70% of the selected V-opening.
This calculator is not intended for bottoming, coining, hemming, offset forming,
radius bending with special tooling, or other special forming processes.