Interactive calculator
Press Brake Air-Bending Tonnage Calculator
Enter the actual bend geometry and tensile strength to estimate total forming force.
Calculated reference
Press Brake Tonnage Chart for 60 ksi Air Bending
Approximate US short tons per foot of bend, calculated from the Bystronic air-bending formula.
Search by decimal thickness. Scroll within the table to compare V openings; an em dash marks combinations outside the 5–19 V/thickness comparison envelope.
No reference thickness matches this search. Enter the actual thickness in the calculator above for a calculated air-bending estimate.
Scroll horizontally to view additional V-opening columns and vertically to view additional thicknesses. Column headers remain visible while scrolling.
| Thickness (mm) | Required air-bending force (US short ton/ft) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.030 in | 0.762 mm | 2.07 | 1.03 | — | — | — | — | — | — | — | — | — | — | — | — | — |
| 0.048 in | 1.219 mm | 5.30 | 2.65 | 1.77 | — | — | — | — | — | — | — | — | — | — | — | — |
| 0.060 in | 1.524 mm | — | 4.14 | 2.76 | 2.07 | — | — | — | — | — | — | — | — | — | — | — |
| 0.075 in | 1.905 mm | — | 6.47 | 4.31 | 3.23 | — | — | — | — | — | — | — | — | — | — | — |
| 0.090 in | 2.286 mm | — | 9.31 | 6.21 | 4.66 | 3.10 | — | — | — | — | — | — | — | — | — | — |
| 0.105 in | 2.667 mm | — | — | 8.45 | 6.34 | 4.23 | — | — | — | — | — | — | — | — | — | — |
| 0.125 in | 3.175 mm | — | — | 12.0 | 8.98 | 5.99 | 4.49 | — | — | — | — | — | — | — | — | — |
| 0.1875 in | 4.762 mm | — | — | — | 20.2 | 13.5 | 10.1 | 6.74 | — | — | — | — | — | — | — | — |
| 0.25 in | 6.35 mm | — | — | — | — | 24.0 | 18.0 | 12.0 | 8.98 | — | — | — | — | — | — | — |
| 0.375 in | 9.525 mm | — | — | — | — | — | 40.4 | 27.0 | 20.2 | 13.5 | — | — | — | — | — | — |
| 0.5 in | 12.7 mm | — | — | — | — | — | — | 47.9 | 35.9 | 24.0 | 18.0 | — | — | — | — | — |
| 0.75 in | 19.05 mm | — | — | — | — | — | — | — | 80.9 | 53.9 | 40.4 | 27.0 | — | — | — | — |
| 1 in | 25.4 mm | — | — | — | — | — | — | — | — | 95.8 | 71.9 | 47.9 | 35.9 | — | — | — |
| 1.5 in | 38.1 mm | — | — | — | — | — | — | — | — | — | 161.7 | 107.8 | 80.9 | 53.9 | — | — |
| 2 in | 50.8 mm | — | — | — | — | — | — | — | — | — | — | 191.7 | 143.8 | 95.8 | 71.9 | — |
| 3 in | 76.2 mm | — | — | — | — | — | — | — | — | — | — | — | 323.4 | 215.6 | 161.7 | 107.8 |
Air-bending estimate only. The Bystronic article does not state a universal thickness range for the formula; Cincinnati separately limits its own calculator to 20 ga through 3 in and V openings of 5–19 times thickness. Verify press-brake capacity, punch and die load limits, flange geometry, bend radius, actual material properties, and manufacturer instructions before production.
Reference-table actions
Live relationship
V-Opening Sensitivity
For the current thickness and tensile strength, compare normalized force from V/t = 5 through 19.
Focus or tap a plotted point to inspect its calculated value.
Press Brake Tonnage Formula and Variables
For conventional air bending, Bystronic publishes the forming-tonnage relationship using inches and a 60,000 psi baseline material. This page applies a method factor of 1.0 and a conventional single-bend tooling factor of 1.0.
T is total US short tons, t is thickness in inches, V is die opening in inches, L is bend length in inches, and S is tensile strength in psi.
- Thickness
- Force changes with thickness squared.
- V opening
- Force changes inversely with die opening.
- Bend length
- Total force scales directly with bend length.
- Tensile strength
- The material factor is tensile strength divided by 60,000 psi.
The calculated value is a forming-force estimate, not proof that a particular press brake, punch, die, part geometry, or setup is acceptable.
Worked Press Brake Tonnage Examples
0.125 in steel baseline
Assume t = 0.125 in, V = 1.000 in, L = 12 in, and S = 60,000 psi.
Result: about 8.98 US short tons.
Sanity check: V/t = 8, which is inside the 5–19 comparison envelope.
Double the bend length
Keep the same thickness, die, and material but increase L from 12 to 24 in.
Result: about 17.97 US short tons.
The force doubles because bend length enters the formula linearly.
Higher tensile strength
Keep the baseline geometry and use S = 90,000 psi.
Result: about 13.48 US short tons.
The material factor becomes 1.5, so calculated force rises by 50%.
V-Die Opening, Material Strength, and Common Mistakes
Do not choose V opening from tonnage alone
A wider V decreases the calculated force, but flange length, inside radius, tooling geometry, material behavior, and bend quality also constrain die selection.
Use actual tensile strength when possible
Material families contain many grades. Enter the tensile strength for the actual material specification instead of assuming one universal multiplier for stainless, aluminum, or steel.
Convert gauge to real thickness first
Gauge is material-dependent. If the drawing or stock list gives only gauge, use the Sheet Metal Gauge Chart to identify nominal thickness for the material before estimating tonnage.
Air bending is not bottoming or coining
This calculator intentionally uses the conventional air-bending method factor. Bottoming and coining can require materially different force and must not be treated as the same calculation.
Engineering References and Calculation Scope
Calculated dataset: conventional air bending, 60,000 psi baseline reference table, formula source checked August 19, 2026.
The table is independently calculated from a published formulation rather than copied from a manufacturer chart. The interactive result scales the same formulation by actual tensile strength.
- Bystronic — How to Calculate Press Brake TonnagePrimary equation basis: 575 coefficient, thickness-squared relationship, die opening, bend length, tensile-strength material factor, and forming/tooling factors.
- Cincinnati Incorporated — Press Brake Tonnage Load CalculatorIndependent manufacturer comparison source confirming air-bend-only use and the input structure of material, thickness, V opening, and bend length.
- Wilson Tool International — Air Bending Force ChartSupporting tooling reference; no Wilson Tool chart data is reproduced here.
Dataset and Source-Check Details
- Publisher
- Turn2Engineering
- Dataset label
- press-brake-air-bend-model-bystronic-2026-08
- Baseline material
- Bystronic baseline: AISI 1035 cold-rolled steel at 60,000 psi tensile strength
- Calculation units
- Canonical inches, psi, and US short tons
- Reference-table scope
- 0.030–3.000 in calculated thickness rows; only cells with 5 ≤ V/t ≤ 19 are displayed
- Rights treatment
- Formula-derived original table; no manufacturer chart reproduced
- CSV status
- Allowed for Turn2Engineering-calculated values
- Known exclusions
- Bottoming, coining, hemming, offset tooling, multi-bend tooling, and machine/tool ratings
Press Brake Tonnage FAQ
There is no single steel tonnage value; the estimate depends on material thickness, V-die opening, bend length, and tensile strength, while final machine and tooling capacity must be checked separately.
For the 60 ksi baseline used here, a 12-inch bend gives tons per foot directly from 575 × thickness² ÷ V opening, with tensile-strength scaling applied for other materials.
V opening is a tooling and geometry decision as well as a tonnage input; use the tooling manufacturer’s guidance for final selection and treat the 5–19 V/thickness range here as a comparison envelope, not a universal design rule.
It can when its tensile strength is higher; this calculator scales force by the actual tensile-strength ratio to 60,000 psi instead of applying a universal material-family multiplier.
No. The chart and calculator are intentionally limited to conventional air bending; bottoming and coining use different forming-force assumptions.
Use the Calculation as a Capacity Check Starting Point
Calculate the forming load from the actual thickness, V opening, bend length, and tensile strength, then verify the press brake and every loaded tooling component against the applicable manufacturer ratings and setup requirements before bending the part.