Aluminum Alloy Seamless Pipe Tube
Seamless aluminum tube/pipe is made without welds. This gives it better strength, pressure resistance, and corrosion performance than welded pipes. Welded pipes, including ERW (Electric Resistance Welded), are made by rolling and welding metal sheets. They have a weld seam, which can be a weak point. Seamless pipes are extruded from solid billets. This creates a uniform structure with no welds. ERW pipes are cost-effective and common in low-pressure uses like fencing or furniture. However, they may not hold up well under high stress or corrosive environments. Seamless aluminum pipes are ideal for tough applications. They are widely used in aerospace, automotive, and fluid systems.
Shenzhen Chinalcometal Seamless Aluminum Tube:
Aluminum alloy :2017,2024 T3 T4 ,3003 H14 H112 ,5052 O H32, 5083 O H112 ,6061 T6 T4 O ,6082,7005,7020,7050,7075 T6 T73 T73511.
Production type:extruded seamless tube ,forged seamless pipe,cold drawn seamless tube, extra Larger diameter (max1500mm) seamless pipe.
Shape: round seamless tube ,square Seamless tube,rectangular seamless tube ,oval seamless tube and customized shape .
Standard : ASTM B210,ASTM B241/B241M,AMSWWT700B,ASTM B221
Seamless Aluminum Pipe Chemical composition
| Alloy | Key Alloying Elements | Category |
|---|---|---|
| 5052 | Mg 2.2–2.8% | Non-heat-treatable corrosion-resistant |
| 5083 | Mg 4.0–4.9%, Mn 0.4–1% | Marine-grade, very high corrosion resistance |
| 6061 | Mg 0.8–1.2%, Si 0.4–0.8%, Cu 0.15–0.4% | Heat-treatable structural |
| 7075 | Zn 5.6–6.1%, Mg 2.1–2.9%, Cu 1.2–2.0% | Highest-strength heat-treatable |
| 2017 | Cu 3.9–4.9%, Mn 0.4–0.9% | High-strength, heat-treatable |
| 2024 | Cu 3.8–4.9%, Mn 1.2–1.8%, Mg 1.2–1.8% | High-strength aerospace alloy |
| 3003 | Mn 1.0–1.5% | Excellent formability, low strength |
| 6082 | Mg 0.6–1.2%, Si 0.7–1.3% | Medium strength, good corrosion resistance |
| 7005 | Zn 4.0–5.0%, Mg 1.0–1.5% | Structural use, heat-treatable |
| 7020 | Zn 5.5–6.1%, Mg 1.2–1.8% | High strength, heat-treatable |
| 7050 | Zn 6.2–6.9%, Mg 2.0–2.6%, Cu 1.2–1.6% | High-strength, aerospace alloy |
Aluminum Seamless Pipe Mechanical properties
| Alloy / Temper | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|
| 5052-O | 193 | 90 | 25–30 | 47 |
| 5083-O | 275 | 125 | 23 | 75 |
| 6061-T6 | 310 | 275 | 10–15 | 95 |
| 6061-O | 110 | 55 | 25 | 30 |
| 7075-T6 | 560–600 | 480–510 | 8–10 | 150 |
| 7075-T73 | 505 | 435 | 10–13 | 140 |
| 2017-T4 | 430–480 | 290–330 | 12–15 | 120 |
| 2024-T3 | 470–530 | 345–375 | 10–15 | 130 |
| 3003-O | 120 | 50 | 25–35 | 25 |
| 6082-T6 | 310 | 275 | 10–15 | 95 |
| 7005-T6 | 490–530 | 420–460 | 10–15 | 120 |
| 7020-T6 | 510–550 | 440–470 | 8–12 | 130 |
| 7050-T7451 | 530–580 | 460–490 | 8–10 | 145 |
Extruded Seamless Aluminum Tube
Extruded seamless aluminum tube is a hollow cylindrical aluminum product made by direct extrusion through a reverse extruder without any welds. Compared with welded tubes, this kind of aluminum tube is stronger and more reliable in high pressure and structural applications.
| Alloy | Temper | Outer Diameter (OD) | Wall Thickness (WT) | Applications |
|---|---|---|---|---|
| 6061 | T6 / T4 / T6511 | 10 – 280 mm | 4 – 60 mm | Aerospace, automotive, structural |
| 6063 / 6082 | T6 | 10 – 260 mm | 4 – 60 mm | Structural, transport |
| 2017 / 2024 | T3 / T4 | 10 – 300 mm | 4 – 60 mm | Aerospace |
| 7020 / 7050 | T6 / T73 | 10 – 300 mm | 4 – 60 mm | Aircraft frames, military |
| 5083 / 5086 | O / H112 | 10 – 260 mm | 4 – 60 mm | Shipbuilding, marine hydraulics |
| 5052 / 3003 | O / H112 | 10 – 200 mm | 4 – 30 mm | Aerospace, automotive, structural |
| 7075 / 7055 | T6 / T6511 | 10 – 300 mm | 4 – 60 mm | Aircraft frames, military |
Forged Seamless Aluminum Pipe
Forged seamless aluminum tube is a hollow cylindrical product produced by forging and extrusion process without welding, free of pores, sand holes, high surface brightness and precision, with the characteristics of high strength, good structural integrity and high reliability in critical applications.
| Alloy Grade | Temper | Outer Diameter (OD) | Wall Thickness (WT) | Length (L) |
|---|---|---|---|---|
| 6061 / 6063 | T6 / T651 | 200 – 1000 mm | 20 – 150 mm | 20 – 1100 mm |
| 5083 | O / H112 | 200 – 1000 mm | 20 – 150 mm | 20 – 1100 mm |
| 2017 / 2024 | T4 / T351 | 200 – 1000 mm | 20 – 150 mm | 20 – 1100 mm |
| 7050 / 7055 | T6 / T7451 | 200 – 1000 mm | 20 – 150 mm | 20 – 1100 mm |
| 7075 | T6 / T73 | 200 – 1000 mm | 20 – 150 mm | 20 – 1100 mm |
Key Characteristics of Forged Seamless Aluminum Pipe
No weld zone Stronger and more corrosion-resistant
High mechanical strength Especially in T6 or T651 tempers
Uniform grain structure Grain flow follows pipe geometry
Pressure resistance Ideal for pressure-critical systems
Good fatigue resistance Excellent for aerospace and structural use
Applications of forged seamless aluminum tube
Aerospace: Hydraulic lines, fuel manifolds, landing gear
Defense: Weapon frames, missile structures
Marine: Ballast systems, underwater tubing
Cryogenics: Liquid hydrogen/oxygen tanks
Oil & Gas: High-pressure delivery systems
Heavy Equipment: Cylinders, pipe systems under cyclic stress
Cold Drawn Seamless Aluminum Tube
Cold Drawn Seamless Aluminum Tube is an aluminum tube manufactured without welding and cold-worked through drawing, which improves dimensional precision, surface finish, and mechanical strength.The tube is pulled through a die and mandrel at room temperature. This process is ideal for high-tolerance and critical structural or fluid-carrying applications.
| Alloy | Temper | Size (OD / WT) | Description |
|---|---|---|---|
| 6061 | T6 / T4 | OD: 6–160 mmWT: 1–10 mm | General-purpose, aerospace & automotive |
| 6063 | T5 / T6 | OD: 6–160 mmWT: 1–10 mm | Excellent surface finish |
| 7075 | T6 / T73 | OD: 6–180 mmWT: 1–10 mm | Very high strength |
| 2017 | T3 / T4 | OD: 6–180 mmWT: 1–10 mm | High strength, fatigue-resistant |
| 2024 | T3 / T4 | OD: 6–180 mmWT: 1–10 mm | High strength, fatigue-resistant |
| 5083 | O / H112 | OD: 6–180 mmWT: 1–10 mm | Marine-grade |
| 3003 | O / H112 | OD: 6–150 mmWT: 1–10 mm | General-purpose, aerospace & automotive |
Cold Drawn Seamless Tube vs Hot Extruded Seamless Tube
Property | Cold Drawn Seamless Tube | Hot Extruded Seamless Tube |
Dimensional Tolerance | Very tight | Moderate |
Surface Finish | Smooth (Ra ≤ 0.8 µm possible) | Rougher |
Strength | Higher (due to cold working) | Lower unless heat-treated |
Formability | Lower than annealed/extruded | Better |
Cost | Higher | Lower |
Application of cold drawn seamless aluminum tube
Aerospace Hydraulic & fuel lines, structural supports
Automotive Shock absorber tubes, steering columns
Medical Prosthetics, surgical instruments
Robotics & Automation Lightweight precision framing
Industrial High-pressure gas lines, instrumentation
Sports & Outdoor Bicycle frames, ski poles, arrows
Extra Larger Diameter Seamless Aluminum Pipe
Extra Large Diameter Seamless Aluminum Tubes refer to seamless extruded or forged aluminum hollow profiles with an outer diameter usually above 200 mm and up to 1500 mm, a wall thickness of 25 mm-300 mm, and a length of up to 18 meters, used in high strength, pressure or structural applications where the integrity of the weld seam is critical.
Aluminum Alloy | Outside Diameter | Wall Thickness | Length |
6061,6063 5083 2017, 2024 7075,7050,7055 | OD:200MM-1500MM | W:25MM-300MM | L:1000MM-18000MM |
Applications of Extra Larger Seamless Aluminum Pipes
Aerospace Rocket motor cases, satellite tanks, airframe cylinders
Marine & Offshore Ballast systems, fluid handling lines, structural arms
Oil & Gas / LNG Cryogenic tanks, high-pressure tubing
Nuclear & Defense Radiation-resistant piping, weapon systems
Heavy Equipment Hydraulic cylinders, boom arms
Architecture & Transport Bridge components, subway infrastructure, monorails
Shenzhen Chinalcometal's key process guarantees:
1.Surface Finish & Cleaning:
We offer a cold-drawn finish with a typical Ra ≤ 1.6 µm, ensuring a smooth, durable surface.
For hydraulic applications, we can achieve an inner bore finish of Ra ≤ 0.8 µm upon request.
2.Straightening & Stress Relief:
Many of our aerospace-grade tubes are delivered in T6511 temper, stress-relieved after stretching, which ensures improved straightness and minimizes distortion during machining.
3.Dimensional Control:
For critical aerospace applications, we adhere to AMS/WW-T tolerance subclasses (e.g., AMS 4079) to ensure exacting precision and close tolerance compliance.
4.Testing & Certification:
We provide comprehensive documentation, including MTC (EN 10204 3.1 / 3.2), tensile test reports, chemical analysis, and Non-Destructive Testing (NDT) (eddy current or ultrasonic), tailored for aerospace and pressure service requirements.
5.End Finishing:
Our tubes can be customized with a variety of end finishes such as chamfered, reamed, deburred, flared, expanded ends, or hydraulic fittings, all produced per customer specifications.
6.Bending & Forming:
For tight bends, we recommend ordering tubes in the O or T4 temper. We advise against bending 7075-T6 tubes (which have low formability) without annealing, ensuring no cracking or distortion.
7.Storage & Handling:
To prevent galvanic corrosion, we ensure proper insulation and dielectric washers for assemblies, particularly when tubes are in contact with dissimilar metals.
FAQ: Seamless Aluminum Tubes
1. What is a seamless aluminum tube? How does it differ from a welded tube?
Seamless aluminum tubes are typically manufactured through piercing and extrusion, while welded tubes are mostly produced using combination-die extrusion. Seamless tubes have a uniform, weld-free structure, which gives them superior pressure-bearing capacity, fatigue strength, and resistance to stress corrosion compared to welded tubes. However, the cost is usually 20%-50% higher.
2. What are the main manufacturing processes for seamless aluminum tubes？
The main processes include:
Hot Extrusion: Aluminum billets are heated and extruded into tubes, suitable for large-diameter tubes.
Cold Rolling / Cold Drawing: Strength is enhanced through cold working, ideal for high-precision or thin-walled tubes (wall thickness can be less than 0.5mm).
Forging: Aluminum billets are pressed using a hammer or hydraulic press to form tube billets, which are then pierced or extruded. This produces a denser metal structure with higher strength, suitable for aerospace, high-pressure hydrogen storage, and other demanding applications.
3. How can the quality of a seamless aluminum tube be evaluated?
Quality is typically judged by:
Dimensional Accuracy: Outer diameter tolerance ±0.1mm, uniform wall thickness.
Mechanical Properties: Tensile strength and elongation meet the alloy specifications.
Internal Quality: Eddy current or ultrasonic testing ensures no pores, cracks, or other defects.
4. Why might the surface of a seamless aluminum tube blister or delaminate?
Common causes include:
Excess gas in the billet or incomplete cleaning of the extrusion container causing gas entrapment.
Poor raw material quality or inadequate heat treatment aging.
Insufficient surface cleaning, which affects coating adhesion.
5. How is cutting precision controlled for thin-walled seamless aluminum tubes?
Thin-walled tubes are prone to deformation. Precision control relies on:
Cutting Equipment: High-precision saws or laser cutting to minimize stress-release deformation.
Fixture Support: Ends are clamped to prevent twisting during cutting.
Cutting Method: Cold cutting is preferred over hot cutting; smooth edges reduce secondary processing.
Dimensional Inspection: Laser diameter measurement or CMM checks ensure length and diameter tolerances are met.
6. What are the advantages of using seamless aluminum tubes in hydraulic or pneumatic systems?
Lightweight: Density is only 1/3 of steel.
High Pressure Capacity: Premium seamless tubes (e.g., 5083 or 6061-T6) can withstand 30-40MPa or higher.
Smooth and Corrosion-Resistant: Ideal for fluid pipelines.
7. What high-end applications commonly use seamless aluminum tubes?
Besides automotive components and bicycle frames, they are widely used in:
Aerospace (landing gear, fuel lines)
Semiconductor equipment (high-purity aluminum tubes for contamination control)
New energy (hydrogen storage cylinders for vehicles)
These industries often require AMS or NADCAP certification.
8. What causes wall thickness non-uniformity (eccentricity) in seamless aluminum tubes?
This is mainly due to insufficient extrusion equipment precision or poor die design. If the extrusion machine spindle is inaccurate or the piercing rod is misaligned with the die centerline, metal flow becomes uneven, causing wall thickness deviation. High-precision hydrogen storage tubes require extremely strict control over this parameter.
