Minimum Bend Radius Calculator
Tightest bend a sheet tolerates before cracking, from its ductility.
Outer fibre strain at radius R is t/(2R+t) — equate it to the material's ductility and R_min falls out. Bend ACROSS the rolling grain to use the full RA; along it, add 50%.
Formula
Minimum Bend Radius Calculator is a free minimum bend radius for design engineers, metallurgists and QA inspectors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Minimum Bend Radius Calculator
Tightest bend a sheet tolerates before cracking, from its ductility. The calculation implements R_min/t ≈ 60/RA − 1 (Datsko's relation) (Datsko & Yang (1960); forming handbooks). Outer fibre strain at radius R is t/(2R+t) — equate it to the material's ductility and R_min falls out. Bend ACROSS the rolling grain to use the full RA; along it, add 50%.
How to use Minimum Bend Radius Calculator
- 1Enter Sheet thickness in mm.
- 2Enter Material reduction of area in % (Annealed steel 60+ · half-hard Al 30 · spring temper 10–15).
- 3Read Minimum inside radius, As multiple of t instantly — no submit button needed.
- 4Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Minimum Bend Radius Calculator?
- ✓Implements the standard formula — R_min/t ≈ 60/RA − 1 (Datsko's relation)
- ✓Reference cited on-page: Datsko & Yang (1960); forming handbooks
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Minimum Bend Radius Calculator use?+
It computes R_min/t ≈ 60/RA − 1 (Datsko's relation), per Datsko & Yang (1960); forming handbooks. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Outer fibre strain at radius R is t/(2R+t) — equate it to the material's ductility and R_min falls out. Bend ACROSS the rolling grain to use the full RA; along it, add 50%.
Where do the material property defaults come from?+
Defaults are standard handbook values (ASM, manufacturer datasheets, the cited standard). Always substitute certified values from your material's test certificate for critical work.
Is the Minimum Bend Radius Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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