Capabilities · Tube Bending
Aluminum tube bending
Mandrel and non-mandrel bending of aluminum tubes and profiles — tight radii, controlled ovality and repeatable angles for frames, fluid lines and enclosures. We bend, then end-form and finish in one job.
What we bend
Our aluminum tube bending service covers round, square and shaped sections used for structural frames, cooling loops, enclosures and handles. On tight radii, mandrel bending inserts a support inside the tube so the wall does not collapse or wrinkle; wiper and pressure dies keep the profile clean through the bend. For larger radii, non-mandrel methods are faster and cost less.
The goal is a bend that holds its shape, its roundness and its angle — batch after batch — without post-bend correction.
Typical parameters
- OD: 6–60 mm typical
- Wall: 0.8–3 mm typical
- Min centerline radius: ~1.5× OD (mandrel)
- Ovality: controlled, measured per spec
Exact limits confirmed against your drawing and material.
How a bend is made
A clean bend is a controlled process, not a single push. Typical flow:
- Plan the bend sequence. Order matters — we lay out hits so a later bend does not foul an earlier one.
- Select method. Mandrel for tight radii and thin walls; non-mandrel for gentle radii and cost.
- Set tooling & overbend. Aluminum springs back, so we program a small overbend and verify the returned angle.
- Bend & measure. Check radius, angle and ovality on the first article; lock the setup.
- End-form (optional). Flare, bead, swage or cut ends to length.
- Finish. Weld, CNC trim, anodize or powder coat as required.
Mandrel vs non-mandrel — which to specify
The choice is driven by radius and wall thickness. Tighter radius and thinner wall need more support inside the tube.
| Method | Best for | Trade-off |
|---|---|---|
| Mandrel | Tight radii (low R/D), thin walls, cosmetic bends | Slower, more tooling, best wall support |
| Non-mandrel (compression / roll) | Gentle radii, thicker walls, cost-sensitive runs | Faster, cheaper; more ovality on tight bends |
As a rule, the smaller the centerline-radius-to-diameter ratio (R/D), the more you need a mandrel. If you only need a slight curve, non-mandrel is usually enough.
Capability & typical specs
Numbers below are typical production ranges; confirm exact limits against your drawing.
| Parameter | Typical capability |
|---|---|
| Method | mandrel / non-mandrel |
| Tube OD | 6–60 mm (typical) |
| Wall thickness | 0.8–3 mm (typical) |
| Min bend radius (R/D) | ≥ ~1.5 (mandrel) |
| Ovality | controlled, measured per spec |
| Secondary | weld, CNC end-form, anodize / powder |
What happens to the wall in a bend
Two effects drive every bend spec: wall thinning on the outside of the curve and wall thickening on the inside, plus a loss of roundness (ovality). Tighter radii and thinner walls make both worse.
| To reduce… | Do this |
|---|---|
| Wall thinning / collapse | Use a larger radius and thicker wall; add a mandrel |
| Ovality | Widen radius, thicken wall, mandrel + wiper die |
| Springback error | Program overbend; verify returned angle on first article |
If a tube must stay pressure-tight or slip-fit after bending, tell us the allowable ovality and wall loss up front — those are the numbers we control to.
DFM notes for bent tubes
Design for bending
- Specify minimum radius only if needed. A larger radius means less wall thinning and lower cost — use the loosest radius your assembly allows.
- Wall ≥ ~1.2 mm resists collapse on tight bends; thinner walls need a mandrel and careful setup.
- Keep bends apart. Leave straight length between bends so tooling clears and the part does not self-interfere.
- Avoid welds on the bend. Weld in the straight section; heat-affected zones bend poorly.
- Define the bend order and datums so the finished part locates correctly in your assembly.
- Allow for springback. We compensate, but confirming the target angle avoids rework.
Where bent aluminum is used
Frames & structures
Roll cages, racks, handles and enclosures where tube geometry replaces welded joints.
Cooling loops
Bent tubes for liquid lines in power electronics and EV charging.
Enclosures
Edge frames and support members with consistent, repeatable angles.
Automation
Guards, conduits and fixture arms needing formed, not fabricated, shapes.
Frequently asked questions
What is the minimum bend radius for aluminum tube?
With a mandrel, a centerline radius around 1.5× the tube OD is a typical practical minimum for thin-wall tube; thicker walls and non-mandrel methods need larger radii. The exact limit depends on OD, wall thickness and alloy — send the section and we confirm.
Mandrel or non-mandrel — which do I need?
Use mandrel bending for tight radii and thin walls where the tube must stay round and wrinkle-free. For gentle radii and thicker walls, non-mandrel is faster and cheaper. The deciding factor is the radius-to-diameter ratio: lower R/D needs more internal support.
How much does the wall thin in a bend?
Wall thinning and thickening are unavoidable — material stretches on the outside and compresses on the inside of the curve. Tighter radius and thinner wall increase both. If a tube must hold pressure or slip-fit, specify the allowable ovality and wall loss and we bend to that.
Can you bend and then weld or anodize?
Yes. We often bend, then weld ends, CNC-trim and finish. Anodizing after bending is fine, but note that welds anodize a different shade — qualify the filler and process together if cosmetic uniformity matters.
What drawing do you need for a quote?
A bend drawing with tube OD, wall, alloy, each bend radius and angle, bend order and end requirements (flare, cut, weld). A 3D model plus a bend table is ideal; we return DFM feedback before production.
Bend your aluminum tubes
Send the bend drawing (R, angle, material) — we quote bending, end work and finishing as one job.