Skip to main content

Metal Bending Prototype

Model flange lengths, neutral axis positions, and bend deductions for sheet metal jobs before committing tooling.

Open utility

metal-bending utility screenshot

What it does​

Experiment with K-factors, bend deductions, and neutral axis positions before sending programs to the press brake. Enter thickness, radius, and angles to see total flat length and per-bend allowances that align with ISO 2768 or ANSI style tolerance blocks.

When to use it (and when not to)​

Use it when:

  • You are drafting or revising press brake programs and want to validate allowances before production.
  • You want to tune K-factor or bend deductions to match a new material batch or brake tooling.
  • You need a quick training aid for apprentices learning how flange lengths change with different radii.

Avoid it when:

  • You are modeling stamped, roll-formed, or highly non-linear bends that need FEA or vendor data.
  • You need automatic flat patterns for complex multi-bend parts; run this per bend and combine the results.

Inputs and outputs​

Inputs​

InputDescription
Material thicknessGauge or thickness of the sheet you are bending.
Inside bend radiusRadius at the neutral axis region; drives allowance values.
Bend angleFormed angle after springback; enter consistent units.
Flange lengthsLeg lengths adjacent to the bend that roll into the flat length.
K-factor or bend deductionChoose to drive calculations with K-factor or a known deduction.
Material or tooling notesOptional notes to remind you of die width, grain direction, or brake setup.

Outputs​

OutputFormatNotes
Total flat lengthNumericLength to program or cut before forming.
Bend allowance / deductionNumericComputed from thickness, radius, and angle for the specified K-factor.
Neutral axis locationNumericPosition expressed as a factor of thickness for reference.
Summary cardOn-screenValues to copy into CAM notes or travelers.

How to use​

  1. Enter sheet thickness and inside bend radius.
  2. Set the bend angle and flange lengths that need flattening.
  3. Choose whether to drive the math from a K-factor or a bend deduction.
  4. Review the resulting flat length and allowance numbers.
  5. Copy the values into your CAM program or save a screenshot for the router.

Example dataset: Thickness: 3 mm, Inside radius: 4 mm, Bend angle: 90 deg, Flanges: 50 mm and 75 mm, K-factor: 0.38.

  • Expected output: Shows flat length and bend allowance for the two-leg bend so you can program the brake or CAM flat pattern.

Accuracy and verification​

  • Assumes air bending with a single K-factor across the bend.
  • Does not account for grain direction or tooling wear; verify with a bent coupon before a full run.
  • Keep your input units consistent; the tool does not convert mixed values.
  • Use press brake test pieces to refine K-factor for each material lot.

FAQ​

  • Does it support multiple bends? Use it per bend or per leg; combine the results for complex parts.
  • Can I work in inch and metric? Yes. Enter values in the units you use; the math is unit-agnostic.
  • How do I export the numbers? Copy them directly from the summary or take a quick screenshot.
  • Does it run offline? Yes. Everything runs locally in your browser.
  • What if my brake uses bend deduction tables? Select bend deduction mode and plug in the table value to see the resulting flat length.

Changelog​

  • Initial documentation.

Feedback / bug report​

LinkedInGitHub