About The Sheet Metal Bend Allowance Calculator

The Sheet Metal Bend Allowance Calculator computes bend allowance, outside setback, and bend deduction from bend angle, inside radius, material thickness, and K-factor.

How to Use the Sheet Metal Bend Allowance Calculator Online

1. Enter bend angle, inside radius, and sheet thickness.
2. Enter the K-factor for the material and tooling setup.
3. Run the calculator to review bend allowance, outside setback, and bend deduction.

Choosing Options Correctly

K-factor depends on material, tooling, bend radius, grain direction, bend method, and shop calibration. For production flat patterns, compare against press brake trials or vendor bend tables.

Common Use Cases

• Estimate sheet-metal flat-pattern values.
• Compare K-factor and radius assumptions.
• Check bend deductions before CAD table updates.

Quick FAQ

Can the bend angle be 180 degrees?
A full 180 degree bend is usually not represented well by the simple bend allowance formula and needs shop-specific tooling data.

Does this replace shop bend tables?
No. It is a calculator for estimates; real flat patterns should use proven K-factors, tooling, material, grain direction, and press-brake data.

How does K-factor affect the result?
K-factor locates the neutral axis through the thickness. A different K-factor changes bend allowance and therefore flat length.

Why might the first part not match the calculation?
Tool radius, material batch, thickness tolerance, springback, bend method, and machine setup can shift the real result.