Welding & Fabrication worked example

Sheet Metal Bend Allowance with bend angle in radians of 3.93 rad: a worked example

What does the result look like when bend angle in radians reaches 3.93 rad? The full calculation is worked below with real intermediate numbers. Use it when developing a flat blank length for a sheet metal part so the bend zone material is accounted for before nesting and shearing.

The inputs for this scenario

  • Bend angle in radians: 3.93 rad (raised for this scenario; the documented default is 1.57)
  • Inside bend radius: 0.13 in (unchanged)
  • Material thickness: 0.07 in (unchanged)
  • K-factor: 0.42 x (unchanged)

Working through the calculation

  • Applying the documented formula (Combined bend zone term = inside bend radius × material thickness × K-factor) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.02 in for sheet metal bend allowance estimate, the number this scenario is built around.
  • At this operating point the engine returns 0.04 value for base product.
  • At this operating point the engine returns 0.42 x for multiplier.
  • At this operating point the engine returns 0.49 value for factor a x b.

How this compares with the baseline

  • Against the tool's baseline example, where bend angle in radians sits at 1.57 rad and the headline result is 0.01 in, this scenario comes in 150% above the baseline at 0.02 in.
  • A figure at this level is achievable when bend angle in radians is genuinely sustained, not just peaked for a shift. The K-factor is empirical and varies with material, tooling, and radius-to-thickness ratio; a book K-factor may not match your actual brake, so verify against a test bend for tight-tolerance work.

Results at a glance

  • Sheet metal bend allowance estimate: 0.02 in (headline result)
  • Base product: 0.04 value
  • Multiplier: 0.42 x
  • Factor A x B: 0.49 value

Run it with your numbers

  • Every input above is editable in the live Sheet Metal Bend Allowance calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.