Tube bending that turns the corner with the metal — not a weld.

Round and square tube in steel, stainless and aluminum, CNC-bent to repeatable radii on mandrel and roll benders. Every bend is checked against a real die library before the quote goes out — so the radius you're promised is one the material actually survives.

Get my tube bending quote →See ranges & radii ↓

Quick definition

Tube bending forms straight tube into a curved part by drawing it around a die on a CNC bender — the process behind handles, furniture frames, guards, roll bars and routed fluid lines. The tube stays one continuous piece: where a welded frame turns a corner with a cut and a weld, a bent part turns it with the metal itself. No joint, no weld to fail, nothing to grind.

One continuous tubeBent, not welded at each corner
The corner is formed from the same tube — no cut, no weld, no joint to fail.
±0.5°typical bend-angle repeatability on a CNC bender, bend after bend across the batch
Ø6–76mmround tube range on mandrel benders; square and rectangular sections run smaller
CLR ≥ 2×Dthe rule of thumb for a clean bend — checked against the real die library before the quote
One pieceeach bend replaces a cut plus a weld — fewer joints, more strength, nothing to grind

What comes off the line

Each curve formed from one continuous length.

No welded corner, no ground seam — the tube turns every corner with the metal itself, so the radii repeat part after part and the wall stays smooth through the bend.

Several brushed stainless steel tubes CNC-bent to consistent radii, including a U-bend and flanged headers, formed as continuous pieces with no welded joints
Round stainless tube bent to matched radii — U-bends and flanged runs formed from one length each, with smooth, wrinkle-free outer walls.

A die, not a fillet

A bend is a tooling decision. Most quotes treat it as a radius in CAD.

Any radius looks fine on screen — whether it survives depends on the die it's drawn around, the wall thickness behind it and the temper of the material. Most shops find that out on the first article. At OperGo, every bend is checked against the die library at quoting: radius, wall and material together, with mandrel and wiper tooling specified when the geometry needs it.

Bent by trial and error
  • A radius picked off a CAD fillet, with no check against any real bending die
  • Wrinkled, collapsed or cracked bends discovered on the first article — not at quoting
  • Instant quoters that simply don't take bent tube
  • End work — holes, notches, flattened ends — sent to a second shop afterwards
The OperGo way
  • Every bend checked against the die library — radius, wall and material together — before the quote goes out
  • Mandrel and wiper dies specified when thin wall or tight radius calls for them, so the bore stays open
  • End-forming, holes, notching and welding priced under the same quote as the bends
  • A corner tighter than the material allows gets flagged and requoted as a cut-and-welded joint instead

What we run

From a tight mandrel bend to a full hoop.

CNC mandrel bending

Thin-wall round tube bent to tight radii without collapsing — an internal mandrel and wiper die keep the bore open and the outside wall smooth.

Roll bending

Large-radius curves, arcs and full hoops — rings, canopy bows and curved rails that a rotary-draw die is too tight for.

End-forming & fabrication

Cut to length, ends flared, swaged or flattened, holes and notches added — the features that turn a bent tube into a finished part, not a blank.

Beyond the bender

A corner tighter than the material allows moves to the tube laser and gets welded; a part that's really sheet moves to the press brake — matched at quoting, not after a cracked bend.

The spec sheet

Tube ranges, radii and tolerances.

Ranges & radii · Tube bendingmandrel + roll
Carbon steel tubeMild steel round and square tube, Ø6mm to Ø76mm, wall 0.8mm to 4mm — the workhorse for frames, guards and brackets, powder coated under the same quote.
Stainless steel tube304 and 316L, bent and then polished or brushed — handles, food-contact frames and marine parts where the bend has to look as good as it holds.
Aluminum tube6060 and 6063 bend cleanly; 6061-T6 and 6082-T6 are flagged at quoting — their temper cracks on tight radii, so those parts run at a larger CLR or in a softer temper.
Bend geometryCenterline radius (CLR) of at least 2× the tube diameter as the rule of thumb, and a straight of roughly one diameter between bends so the die can grip — both confirmed against the die library at quoting.
ToleranceBend angle typically ±0.5°, with end-to-end feature positions held against your 2D drawing. Springback is compensated per material and batch on the CNC bender, not guessed.
Beyond bendingLaser-cut features, welding to other members and finishing — powder coat, anodizing, polishing — specified and priced under the same quote as the bends.

Full range of materials and finishes on Materials & finishes →

Picking a process

A bend is the right call — until it isn't.

Bent tube vs. welded corners →

One continuous bent member is stronger, cleaner and usually cheaper than cutting and welding the corner — as long as the radius is open enough for a die. Tight corners and multi-tube junctions go the other way: tube laser plus welding.

Tube bending vs. sheet metal bending →

Sheet metal bending folds flat blanks on a press brake; tube bending curves hollow sections around a die. An enclosure or bracket is sheet metal — a handle, frame member or routed line is tube.

Still not sure?

Send the part and an engineer matches it to the right process — and if a bend won't survive your material and radius, they say so at quoting, not on the first article.

Tube bending, answered

What's the minimum bend radius for a tube?

The working rule is a centerline radius (CLR) of at least 2× the tube diameter — tighter is possible with a mandrel and the right wall thickness, but it costs more and not every material survives it. Your bend is checked against the actual die library at quoting, so the radius on the quote is one a real die can form.

How do you keep the tube from wrinkling or collapsing?

With tooling, not luck: an internal mandrel supports the bore through the bend and a wiper die backs up the inside wall where wrinkles start. Whether they're needed depends on the ratio of diameter to wall thickness and how tight the radius is — your engineer specifies them when the geometry calls for it, and prices them in.

Can you bend square or rectangular tube?

Yes — square and rectangular sections bend on the same rotary-draw benders with section-specific dies to control twist and keep the faces flat. The practical size range is smaller than for round tube, and tight radii are harder on the outer face, so square-tube bends get checked against the die library case by case.

Can 6061-T6 or 6082-T6 aluminum tube be bent?

Not reliably at tight radii — the T6 temper cracks on the outside of the bend. The standard moves are a larger CLR, a softer temper bent then aged, or switching the part to 6060/6063, which bend cleanly. Your engineer flags this at quoting rather than letting it fail on the first article.

Do you also cut, drill and weld the bent parts?

Yes — cut to length, holes, notches, end-forming and welding to other members are specified against the same drawing and priced in the same quote. A bent tube that needs laser-cut features or a welded bracket doesn't become a second vendor's problem.

What files do I need to send?

A STEP file of the part plus a 2D PDF drawing with the critical dimensions. The bender's data — bend angles, rotations and straight lengths — is extracted from your STEP geometry by the engineer, so you don't need to supply a bend table.

What's the minimum order quantity?

There's no fixed minimum — price is what naturally limits a very small order, not a policy. One bent handle is quoted the same way a batch of a thousand frame members is.

Straight members? Tube laser cutting →

Cut, coped and welded frames — quoted as one part, not a pile of sticks.

Folding sheet, not tube? →

Enclosures, brackets and panels formed on a press brake from a laser-cut blank.

See all capabilities →

Tube laser, sheet metal, CNC machining and everything else we run.

Materials × process

Materials we run in tube bending.

Sourced, produced and finished under one quote. Tap a material to see the other processes it runs on — material and process are two axes you combine, not one nested inside the other.

SteelStainless SteelAluminumAll materials & finishes →

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