What is a Rolla-V type die?
A Rolla-V type die is an adjustable V die in which rotating or movable inserts change the effective opening, so one die covers several V widths. Rolla-V is a trade name of its manufacturer; this page describes the die category generically.
What does an adjustable V die do?
It changes its effective opening without being removed from the machine, so the operator can move between radii and thicknesses quickly. Some designs also close the included angle, which corrects springback.
| Benefit | How it is achieved | Trade-off |
|---|---|---|
| Several openings in one die | Rotating or sliding inserts | Taller and heavier than a single-V die |
| Fast changeover | No die change between jobs | Higher initial cost |
| Springback correction | Inserts close the included angle | More mechanism to maintain |
| Variable radius | Effective opening changes | Radius range is bounded by the die |
When is an adjustable die worth the cost?
When the shop changes radius or thickness often enough that die changes are a real time cost, or when one machine has to cover a wide range of work. For a single repeating job, a fixed die is cheaper and more rigid.
- High mix, low volume: the strongest case for an adjustable die.
- Fast setup targets: removing the die change helps directly.
- Variable radius work: a fixed set of dies would be expensive and slow.
- Single fixed job: a fixed die is stiffer and cheaper.
Are adjustable dies as strong as fixed dies?
Usually rated somewhat lower, because the mechanism occupies space that would otherwise be solid steel. The rated load per metre is stated for each opening, and it changes as the opening changes.
What is the difference between a Rolla-V type die and a multi-V die?
A multi-V die presents several fixed openings in one body, and you use the one you need. An adjustable die has one opening whose width or angle can be changed. Multi-V is cheaper and more rigid; adjustable is more flexible.
| Adjustable / Rolla-V type | Multi-V | |
|---|---|---|
| Openings | One, continuously variable | Several, fixed |
| Radius | Variable within a range | Fixed by the machined openings |
| Springback control | Possible by closing the angle | Not provided |
| Rigidity | Lower | Higher |
| Cost | Higher initial cost | Lower initial cost |
Related technical pages
Press brake dies
Fixed single-V, 2V and multi-V dies compared.
Radius dies
Fixed-radius shoulders for a controlled radius.
Springback guide
Why closing the included angle corrects the bend.
Custom tooling
Purpose-made dies when neither type fits.
Next step
Tell us the range of thicknesses and radii you bend and we will advise whether an adjustable die or a multi-V set is the better investment.
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