TOOLS / SHEET METAL

Sheet metal bend allowance calculator

Estimate bend allowance, bend deduction and flat blank length for a sheet-metal bend.

Estimate the flat blank length for one sheet-metal bend.

Bend allowance4.46 mm
Bend deduction3.54 mm

Flat length becomes available in Intermediate mode.

Use the actual tooling, material and test-bend data for production. K-factor varies with material and forming method. Typical K ranges: soft materials about 0.30-0.38, mild steel about 0.40-0.45, stainless about 0.42-0.48, hard materials about 0.44-0.50 — these are starting ranges only, not a substitute for a test bend on your tooling. Always verify with a test bend before production.

Built for practical decisions

Bend development depends on thickness, inside radius, bend angle and the neutral-axis K-factor. This tool keeps those assumptions visible so a fabricator can adjust them to match actual tooling.

Important assumptions

Use the result as a planning estimate. Confirm material data, machine settings, drawing tolerances and applicable standards before production or structural work.

Quick answers about this sheet metal bend allowance calculator

What does the sheet metal bend allowance calculator help me decide?

Estimate bend allowance, bend deduction and flat blank length for a sheet-metal bend.

Can I use the result directly for production?

Use it as a starting estimate. Verify the drawing, material grade, machine capability, tooling data and applicable standard before cutting, forming, welding or ordering material.