To bend a flange with an irregular shape, add a flat reference edge parallel to the bend line. You can either modify your design to create a straight edge or add break-off tabs that you’ll remove after receiving your part.
Oddly shaped flanges can be bent — but our press brake tooling needs a flat, parallel reference edge along the bend line. This edge ensures your flange is properly supported during bending and prevents distortion.
You can:
- Revise your design to create a flat edge, or
- Add break-off tabs (material extensions with connecting bridges) that are removed after you receive the part.
Note: We don’t remove break-off tabs. If you add finishing services, the raw edge beneath the tab will be visible after removal.
Best practices for break-off tabs
If you choose to add break-off tabs instead of revising an oddly shaped flange edge to create a flat parallel surface, follow these best practices!
1. Create enough tab length
Minimum break-off tab length depends on your part’s flat length:
- 0–5 inches: 0.500″ minimum breakoff tab
- 5–10 inches: 1.000″ minimum breakoff tab
- 10+ inches: 1.500″ minimum breakoff tab
We may request a longer tab if needed for your design’s geometry.
2. Add enough connecting bridges
- Create a minimum of 2 bridges for flanges up to 10″ long
- Add 1 extra bridge for every additional 10″ of flange length
3. Make bridges wide enough
- Width: at least 0.040″ or your material’s minimum bridge widt, whichever is larger. If bridges are too thin, they may break during the bend operation.
- For materials 0.080″ or thicker: bridges should be ≤ 50% of the material thickness
4. Keep bridges out of die lines
- Bridges inside the press brake die area can break during bending. Place them outside die lines for stability.
5. Add breakoff tabs the part exterior
- We can’t use break-off tabs placed on the interior of a part. See our Window Bend Requirements for more on interior bend limitations.
6. Special note for polycarbonate
- Remove tabs using a cut-off wheel or saw, not side cutters — polycarbonate can crack under shearing force
Why this matters
A flat, parallel edge allows our tooling to grip your flange evenly, producing a cleaner bend and avoiding deformation. Break-off tabs give you the flexibility to keep your original flange shape while still meeting our bending setup requirements.
Evening out those odd flanges!
Odd flanges can certainly make your parts stand out, so follow our advice here to ensure we can bend them! Review our full bending guidelines before uploading your part file to our website for an instant quote. If you have questions, ask our Support team anytime!