What is a urethane press brake die?
A urethane die has an elastomer insert in place of the V opening. The insert wraps the sheet around a radius under load, so the outer surface is never pressed against a steel shoulder and is not marked.
When should I use a urethane die?
Use one when the part has a cosmetic face that must not be marked, when the material is coated or polished, or when a large radius is acceptable and a mark-free finish is essential.
| Application | Why |
|---|---|
| Pre-painted or coated sheet | Steel shoulders would damage the coating |
| Polished stainless and aluminium | No shoulder contact means no scuffing |
| Visible architectural panels | The finished face must stay unmarked |
| Large-radius bends | The insert forms the radius naturally |
How does a urethane die differ from a steel die?
The forming geometry comes from the elastomer deforming under load rather than from a machined V. The resulting radius is larger and depends on the load, the thickness and the insert hardness.
| Urethane die | Steel V die | |
|---|---|---|
| Radius | Large, load dependent | Set by the opening |
| Surface marking | Minimal | Possible at the shoulders |
| Pressure range | Limited by the insert | Limited by the tool rating |
| Consistency | Sensitive to material and load | Highly repeatable |
| Typical use | Cosmetic and coated sheet | General production |
What are the limits of a urethane die?
The insert has a pressure limit, and exceeding it damages the elastomer permanently. The achievable radius is larger than a steel die would give, and the result is more sensitive to material variation.
Can I bend thick material with a urethane die?
Only within the insert's pressure rating, which is lower than a steel die of the same size. Thick or high-strength material usually needs a steel die, with the marking problem solved another way.
- Check the insert's rated pressure before running a new job.
- Reduce the bend length if the total force is too high.
- For thick material, use a wider steel opening and an anti-mark film instead.
- Replace the insert when it shows permanent deformation.
Related technical pages
Anti-mark tooling
Other ways to protect a cosmetic face.
Press brake dies
Steel die types compared.
Radius dies
A steel alternative when a controlled radius matters more than the finish.
Tonnage calculator
Check the force against the insert rating.
Next step
Send a sample of the material and the finish requirement and we will advise between a urethane die and an anti-mark steel setup.
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