Every week at Aluminium Tubes, the same phone call arrives from an HVAC contractor or panel builder: “I need soft aluminium tubing in a coil — what sizes do you actually have?” Fair question. Coiled aluminium tubing follows a size system inherited from refrigeration practice — imperial ODs, gauge-numbered walls, coil lengths in both metres and feet — and no two supplier catalogues present it the same way.
This guide ends the confusion. Below you’ll find the complete size chart — outside diameters in inches and millimetres, standard wall thicknesses, coil lengths, and per-coil weights — followed by the grade comparison (1100 vs 3003 vs 5052), the temper rule that decides whether your coil bends by hand, and the uncoiling and flaring techniques that keep soft tube kink-free.
Whether you’re running refrigerant lines in Dubai heat, plumbing a pneumatic panel, or feeding a heat-exchanger line, the chart below is the one to print. And if your size isn’t on it, Aluminium Tubes supplies custom coils against the same standards — more on that at the end.
Table of Contents
- What Is Coiled Aluminium Tubing?
- The Complete Size Chart
- How to Read the Chart (4 Steps)
- Grade Guide: 1100 vs 3003 vs 5052
- The Temper Rule: Why O Means Easy
- Coiled Tubing vs “Aluminium Coil” — Not the Same Product
- Working With Coils: Uncoiling, Bending, Flaring
- Where Coiled Tubing Is Used
- Key Takeaways
- FAQ
What Is Coiled Aluminium Tubing?
Coiled aluminium tubing is small-diameter aluminium tube — typically 1/8″ to 3/4″ (3–20mm) OD — supplied wound into compact coils rather than straight lengths. Made from soft-temper alloys like 3003-O and 5052-O, it bends by hand, cuts anywhere along its continuous length, and ships 15–50 metres in a box instead of six-metre sticks on a truck.
The coil format exists for three practical reasons. First, continuous length: a 30-metre refrigerant run needs no joints, and every joint you don’t make is a leak you’ll never chase. Second, logistics: coils travel by courier; straight lengths need freight. Third, workability: soft coiled tube routes around obstacles the way rigid tube simply can’t.
Two coil formats dominate. Pancake coils wind flat and spiral — the refrigeration standard. Level wound coils (LWC) stack layers neatly on a core for machine uncoiling in production lines. Same tube, different winding — specify which when you order.
The Complete Coiled Aluminium Tubing Size Chart
Sizes follow refrigeration-trade convention: imperial OD, wall in inches (with mm equivalents), soft temper unless stated. Weights are calculated for aluminium at 2.71 g/cm³.
| OD (inch) | OD (mm) | Standard Walls | Weight (kg/m) | Common Coil Lengths | Approx. Coil Weight (15m) |
|---|---|---|---|---|---|
| 1/8″ | 3.18 | 0.030″ (0.76mm) | 0.016 | 15m / 50ft | 0.24 kg |
| 3/16″ | 4.76 | 0.030″ (0.76mm) | 0.026 | 15m / 50ft | 0.39 kg |
| 1/4″ | 6.35 | 0.030″ (0.76mm) | 0.036 | 15m / 30m / 50ft / 100ft | 0.54 kg |
| 5/16″ | 7.94 | 0.032″ (0.81mm) | 0.049 | 15m / 30m / 50ft | 0.74 kg |
| 3/8″ | 9.52 | 0.032″ (0.81mm) | 0.060 | 15m / 30m / 50ft / 100ft | 0.90 kg |
| 1/2″ | 12.70 | 0.035″ (0.89mm) | 0.090 | 15m / 30m / 50ft | 1.34 kg |
| 5/8″ | 15.88 | 0.035″ (0.89mm) / 0.049″ (1.24mm) | 0.114 / 0.155 | 15m / 30m / 50ft | 1.70 kg |
| 3/4″ | 19.05 | 0.049″ (1.24mm) | 0.188 | 15m / 30m | 2.82 kg |
| Metric 6mm | 6.00 | 1.0mm | 0.043 | 15m / 30m | 0.64 kg |
| Metric 8mm | 8.00 | 1.0mm | 0.060 | 15m / 30m | 0.90 kg |
| Metric 10mm | 10.00 | 1.0mm | 0.077 | 15m / 30m | 1.15 kg |
| Metric 12mm | 12.00 | 1.0 / 1.5mm | 0.094 / 0.134 | 15m / 30m | 1.41 kg |
Weight formula for any size not listed: kg/m = 0.00851 × (OD − wall) × wall, both in millimetres. A 10mm × 1mm tube: 0.00851 × 9 × 1 = 0.077 kg/m — multiply by coil length and you’ve estimated your shipment before asking anyone.
How to Read the Chart (4 Steps)
- Match the OD to your fittings, not your memory. Refrigeration flare fittings are sized by tube OD — a “3/8 line” means 3/8″ OD (9.52mm), never ID. Metric compression fittings likewise grip the OD.
- Pick the wall by pressure and flaring. Standard walls (0.030–0.035″) suit refrigerant and instrument pressures comfortably; step up to 0.049″ for higher-pressure circuits or mechanical abuse zones.
- Choose coil length by run, plus 10%. Joints are failure points — buy the coil that completes your longest run in one piece, with slack for routing.
- Confirm temper O for hand work. The chart assumes soft temper; an H14 coil of the same size behaves like a different product entirely (next sections explain).
Grade Guide: 1100 vs 3003 vs 5052
| Property | 1100-O | 3003-O | 5052-O |
|---|---|---|---|
| Tensile Strength | ~90 MPa | ~110 MPa | ~195 MPa |
| Hand Bendability | Exceptional | Excellent | Very good |
| Corrosion Resistance | Excellent | Excellent | Excellent — best in salt air |
| Typical Duty | Instrument lines, low pressure | The HVAC/refrigeration standard | Fuel lines, marine, higher pressure |
In practice the decision is simple. 3003-O is the default — it’s what “refrigeration-grade aluminium coil tubing” means in the trade, balancing bendability, strength, and cost. Step up to 5052-O when the line carries fuel, lives near the coast, or needs nearly double the burst margin — the same strength-with-formability logic from our 5052 comparison guide, scaled down to tube. Drop to 1100 only for low-pressure instrument work where maximum softness helps.
The Temper Rule: Why O Means Easy
Here’s the specification detail that catches first-time buyers. The same 3/8″ 3003 tube ships in two tempers, and they’re different animals:
- O (annealed): Bends around your thumb, flares without cracking, uncoils by hand. This is what coiled tubing means by default.
- H14 (half-hard): Nearly double the strength — and it fights every bend, springs back hard, and risks cracking on tight flares.
Order coils in O temper unless an engineer has specified otherwise for pressure reasons. If you need both bendability and strength, the professional route is bending in O and accepting the pressure maths, or moving up a wall thickness — per the radii in our aluminium tube bending radius chart, where soft 3003 wraps down to 1–1.5× its diameter.
Coiled Tubing vs “Aluminium Coil” — Not the Same Product
A confusion we untangle weekly: search “aluminium coil” and half the results are flat sheet wound into rolls — cladding and jacketing material — not tube at all. The terms matter when you’re ordering:
- Coiled tubing (this guide) = hollow tube, wound for convenience → fluids flow through it.
- Aluminium coil = flat strip/sheet in roll form → it becomes roofing, ducting, jacketing. That product lives on our 3003 aluminium coil page.
Write “coiled tubing” or “tube coil” on enquiries and you’ll never receive a quotation for the wrong product.
Working With Coils: Uncoiling, Bending & Flaring
Uncoiling Without Kinks
Never pull tube off a stationary coil like rope — that twists the tube once per turn, and twist becomes kinks. Instead, lay the pancake flat and roll it along the floor, paying tube out straight, or rotate the coil on a simple spindle while you walk the free end away. Thirty seconds of technique saves metres of scrap.
Bending Soft Coil Tube
Hand bends to generous radii are fine in O temper. For tight, repeatable bends use a spring bender slid over the tube or a lever bender — full technique in our bending without kinking guide. Keep radii at or above the chart minimums and the bore stays round.
Flaring for SAE Fittings
Aluminium flares beautifully in O temper: cut square with a tube cutter (light passes — aluminium cuts faster than copper), deburr inside and out, slip the flare nut on first, then form a 45° SAE flare with steady, moderate force. Over-tightening the flare tool work-hardens the seat and invites cracks — snug, not strangled.
Where Coiled Aluminium Tubing Is Used
- HVAC & refrigeration: Condensate lines, refrigerant circuits, and the pancake coils inside split-AC installations across Gulf summers.
- Pneumatics & instrumentation: Control air, gauge lines, sample tubing in panels — continuous runs, zero joints.
- Fuel and brake lines: 5052-O coils flared to SAE fittings in automotive and equipment builds.
- Heat exchangers: Coil-wound circuits for chillers and process cooling, often starting as drawn tube for wall precision before winding.
- Medical and laboratory gas: Clean, continuous small-bore runs where joint count is a contamination budget.
Key Takeaways
- ✔ Coiled aluminium tubing runs 1/8″–3/4″ OD (plus 6–12mm metric), walls 0.030″–0.049″, in 15m/30m/50ft coils.
- ✔ Estimate any weight with kg/m = 0.00851 × (OD − wall) × wall (mm).
- ✔ 3003-O is the trade default; 5052-O for fuel, coast, and pressure; 1100 for maximum softness.
- ✔ O temper = hand-workable. H14 is a different product — confirm temper on every order.
- ✔ Roll coils to uncoil, never pull; flare nut on before flaring; radii per the bending chart.
- ✔ “Coiled tubing” is hollow tube — “aluminium coil” is flat sheet. Say the right words, get the right quote.
Frequently Asked Questions
What sizes does coiled aluminium tubing come in?
Standard coiled sizes run from 1/8″ to 3/4″ OD (3.18–19.05mm), with metric 6–12mm equivalents, in walls from 0.030″ to 0.049″ (0.76–1.24mm). The workhorse trio is 1/4″, 3/8″, and 1/2″ — stocked everywhere in 15m and 50ft pancake coils, with 30m and 100ft for long runs.
How long is a coil of aluminium tubing?
Common coil lengths are 15 metres and 30 metres (metric markets) or 50ft and 100ft (imperial practice). Small diameters coil longer; 3/4″ tube usually tops out at 30m per coil for handling weight. Custom lengths are a mill order — ask when your run needs one unbroken piece.
Is 3003 or 5052 better for coiled tubing?
3003-O is the industry default for HVAC and general service — maximum bendability at adequate strength. Choose 5052-O when the line carries fuel, operates near salt air, or needs nearly double the pressure margin; it bends almost as easily and flares just as well.
Can you straighten coiled aluminium tubing?
Yes. For short runs, roll the coil out flat and hand-straighten; for neat results, pull the tube through a simple three-roller straightener. Soft O-temper tube straightens without damage — just avoid repeated bend-straighten cycles in one spot, which work-hardens the metal locally.
What pressure can coiled aluminium tubing handle?
It depends on diameter, wall, and alloy. As working examples with a 4:1 safety factor: 1/4″ × 0.030″ in 3003-O handles roughly 30–40 bar; the same size in 5052-O roughly doubles that. For refrigerant circuits, follow the system standard your engineer specifies — and ask us for calculated ratings on your exact size.
Can you flare aluminium tubing like copper?
Yes — O-temper aluminium flares as readily as soft copper using the same 45° SAE tools. Cut square, deburr thoroughly, fit the nut before flaring, and form with moderate pressure. The one difference: aluminium work-hardens faster, so form the flare in one smooth operation rather than repeated attempts.
What is the difference between coiled tubing and aluminium coil?
Coiled tubing is hollow tube wound into coils — fluids flow through it. “Aluminium coil” in trade language means flat sheet or strip wound into rolls, used for cladding, jacketing, and forming. They’re entirely different products that share a word — specify “tube coil” to avoid misquotes.
Which temper should I order for hand bending?
O temper (fully annealed), always, for hand-formed work — it bends to tight radii and flares without cracking. H14 half-hard coils exist for straight protected runs needing extra strength, but they resist bending and spring back. If the box doesn’t state the temper, ask before you buy.
Does coiled aluminium tubing corrode with copper fittings?
Direct aluminium-to-copper contact in damp conditions creates a galvanic couple, with aluminium sacrificing. Use approved transition fittings or dielectric unions on mixed-metal systems, and keep joints dry and insulated. All-aluminium circuits avoid the issue entirely — one reason the HVAC industry keeps moving our way.
Conclusion: One Chart, Zero Guesswork
Coiled aluminium tubing isn’t complicated once the system is in front of you: imperial ODs from 1/8″ to 3/4″, soft O temper for hand work, 3003 as the default grade, and a weight formula that estimates any coil before you’ve asked for a quote. Print the chart, confirm OD-wall-temper-length on every order, and the product does exactly what fifty years of refrigeration practice refined it to do.
Aluminium Tubes supplies the full chart — pancake and level wound coils in 1100, 3003, and 5052, O and H14 tempers, certified to ASTM B210/B483 and EN 754 with EN 10204 3.1 Mill Test Certificates — plus custom ODs, walls, and coil lengths against mill order for OEM production. Browse the range on our coiled aluminium tubes page, or send your size list straight to the team.
Need coils this week? WhatsApp +91 95166 18000 or email support@aluminiumtubes.org — and get size-matched, certified coil pricing from Aluminium Tubes within 24 hours →