Leak and burst
Tube and manifold sections destined for pressurised circuits are leak-tested or burst-tested to the pressure in the customer specification.
Automotive heat-exchanger extrusions
3005 H112 Aluminium Profiles for Automotive Use
3005 is an aluminium-manganese-magnesium alloy that is about 20 % stronger than 3003 while keeping its corrosion resistance, brazeability and good thermal conductivity. As H112 extrusions it is used for coolant tube, header and manifold sections and small brackets in radiators, heater cores and air-conditioning systems. Metline supplies 3005 profiles and tube cut to length and certified to vehicle and heat-exchanger makers worldwide.
- Alloy
- 3005 (Al-Mn-Mg)
- Temper
- H112 (as extruded), O
- Standards
- GB/T 33910 · ASTM B221 · EN 755
- Main use
- Cooling and HVAC parts
What is 3005 aluminium, and why is it used in vehicles?
3005 belongs to the 3xxx family, where manganese is the main alloying element. It adds 0.2 – 0.6 % magnesium to the 1.0 – 1.5 % manganese base of 3003, and that magnesium gives a useful step up in strength without making the alloy heat-treatable. Strength therefore comes from the alloy content and, in rolled tempers, from cold work.
In automotive engineering 3005 is best known as heat-exchanger material: radiator and heater tube, header plates, side supports and fin stock are made from it, either bare or as the core of clad brazing sheet. The extruded form covers the parts that are easier to make as a profile than from strip, such as round and oval coolant tube, manifold and header sections, end tanks for small coolers and simple brackets that must survive the brazing furnace alongside the core.
The H112 temper means the profile is used as extruded, with no deliberate cold work or annealing but with tested mechanical properties. That suits brazed assemblies well: any cold-worked strength would be lost in a furnace cycle near 600 °C anyway, so designers work with annealed-level properties for the finished part. Where a part is not brazed, 3005 H112 still offers a little more strength than 3003 at almost the same cost.
3005 chemical composition (wt %)
3005 is registered with the Aluminum Association and appears in EN 573-3 as EN AW-3005 (AlMn1Mg0,5). The same limits are adopted in GB/T 3190. Every Metline lot is certified with the measured analysis.
| Element | Minimum | Maximum | Role in the alloy |
|---|---|---|---|
| Silicon (Si) | — | 0.6 | Impurity; affects brazing behaviour and extrudability |
| Iron (Fe) | — | 0.7 | Impurity; forms Al-Fe-Mn particles |
| Copper (Cu) | — | 0.30 | Small addition raises strength and makes the core more noble |
| Manganese (Mn) | 1.0 | 1.5 | Main alloying element: strength, sag resistance, corrosion behaviour |
| Magnesium (Mg) | 0.20 | 0.6 | Extra solid-solution strength over 3003 |
| Chromium (Cr) | — | 0.10 | |
| Zinc (Zn) | — | 0.25 | |
| Titanium (Ti) | — | 0.10 | |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 95.7 – 98.8 % |
Magnesium above roughly 0.3 – 0.5 % can interfere with fluxes used in controlled-atmosphere (Nocolok-type) brazing, because it reacts with the flux. For brazed parts, agree the magnesium level and the flux system with the brazer before ordering.
Mechanical and physical properties of 3005
As-extruded H112 properties lie close to the annealed condition, and they vary somewhat with section and extrusion conditions. For that reason the tested minimums are agreed on the drawing or taken from the governing order standard, and are reported on the certificate for each lot. The typical values below show where 3005 sits relative to its rolled tempers.
| Condition | Tensile strength (typical) | Yield strength 0.2 % (typical) | Elongation (typical) |
|---|---|---|---|
| O (annealed) – also post-braze reference | about 130 MPa | about 55 MPa | about 25 % |
| H112 extrusion | close to O values, slightly higher | close to O values | high; measured per lot |
| H14 (rolled, for comparison) | about 180 MPa | about 165 MPa | about 7 % |
| H18 (rolled, for comparison) | about 240 MPa | about 225 MPa | about 4 % |
Older catalogues sometimes quote a single wide band such as "120 – 200 MPa" for 3005 H112 profiles. Such ranges mix different tempers; design brazed parts to O-temper values and unbrazed parts to the tested minimum on the certificate.
Physical properties (approximate)
- Density
- 2.73 g/cm³
- Melting range
- about 630 – 655 °C
- Thermal conductivity
- about 160 W/m·K (O temper)
- Electrical conductivity
- about 40 – 42 % IACS
- Coefficient of thermal expansion
- about 23.2 µm/m·°C (20 – 100 °C)
- Modulus of elasticity
- about 69 GPa
3005 profile sizes, shapes and finishes
Typical supply range for 3005 profiles
- Temper
- H112 (as extruded); O (annealed) for tube that will be bent or expanded
- Section types
- Round, square and rectangular tube; angle, channel, T and I sections; flat bar; hollow and multi-cavity custom profiles to drawing
- Size envelope
- Small trim and tube sections up to large structural profiles; the feasible circumscribing circle and wall depend on the die and press, and are confirmed at quotation
- Wall thickness
- From about 1 mm on small sections; thicker walls on structural shapes
- Length
- Standard 6 m mill lengths; cut-to-length parts and longer lengths on request
- Finish
- Mill finish, anodised, anodised and electrophoretic lacquer, powder coated or wet painted
- Processing
- Precision sawing, punching, CNC machining, bending and deburring to drawing
Every custom profile is drawing-specific. Send the section drawing with critical dimensions and tolerances so feasibility can be confirmed.
Profiles for automotive use are almost always made to a customer drawing. Round and oval tube for coolant lines, D-shaped and rectangular manifold sections and flat-oval tube for small coolers are the most common 3005 shapes. Where the part will be anodised or painted, tell us which faces are visible so that die orientation and handling can protect them.
Tolerances, cleanliness and testing
Unless the drawing states tighter values, profile dimensions follow the general tolerance tables of the order standard. Automotive programmes often add their own limits on critical features such as mounting faces, wall thickness at crush zones and twist over the part length. Heat-exchanger parts also need clean internal surfaces: extrusion debris left inside a manifold or tube can block channels or contaminate the brazing flux.
Tolerance and inspection references
- Cross-section tolerances
- EN 755-9 (profiles), ASTM B221 with ANSI H35.2, or GB/T 14846 for orders to Chinese standards
- Straightness and twist
- Per the same tables, or as agreed for long automotive parts
- Surface quality
- Visible faces free of die lines, pick-up and blisters beyond the agreed limit sample
- Mechanical testing
- Tensile test per lot to ISO 6892-1 or ASTM B557; hardness checks on request
- Certification
- EN 10204 3.1 mill test certificate with chemistry and mechanical results
Corrosion testing
Coolant-side and external corrosion life is typically proven with tests such as SWAAT (ASTM G85 Annex A3) or neutral salt spray (ASTM B117), with hours set by the vehicle maker.
Traceability
Each bundle is labelled with alloy, temper, lot and date, and matched to its 3.1 certificate.
Brazing, welding, bending and finishing
Brazing
3005 brazes well with 4343 or 4045 filler from clad sheet or paste. Control magnesium (see note above) when using non-corrosive flux. Post-braze strength is roughly that of the O temper.
Welding
TIG and MIG welding are straightforward with ER4043 or ER1100-type fillers. The heat-affected zone softens to annealed strength, which is close to H112 anyway.
Bending and forming
H112 and O tube bend readily with mandrel support; flaring, beading and end-forming of coolant tube are routine.
Machining
Soft and gummy like other 3xxx alloys. Use sharp, high-rake tools and good lubrication for clean cuts and threads.
Surface finishing
Accepts powder coat, wet paint and conversion coatings. Anodising gives a slightly greyer film than 6xxx alloys because of the manganese.
Corrosion protection
Zinc-rich surfaces, sacrificial fins or coatings are commonly used in heat-exchanger designs to delay pitting perforation.
Where 3005 profiles are used in vehicles
- Radiators and heater cores: coolant tube, header and side-plate sections, and small end tanks for brazed cores
- Air-conditioning systems: manifold and receiver-drier sections and connection tube in brazed condenser assemblies
- Coolant and oil lines: bent and end-formed tube for engine, transmission and EV thermal circuits
- EV battery thermal management: manifolds and distribution tube feeding cold plates
- Brackets for brazed assemblies: mounting parts that must go through the brazing furnace with the core
- Trim and covers: light-duty trim strips and covers where a painted 3xxx alloy is sufficient
Exhaust systems are sometimes listed for 3005, but in practice exhaust pipes run far too hot for aluminium alloys; aluminised or stainless steel is used there. 3005 belongs on the coolant and air-conditioning side of the vehicle.
3005 compared with 3003, 3105 and 6063
| Property | 3003 | 3005 | 3105 | 6063-T5 |
|---|---|---|---|---|
| Alloy type | Al-Mn | Al-Mn-Mg | Al-Mn-Mg (lower Mn) | Al-Mg-Si (heat-treatable) |
| Typical tensile, annealed / as used | about 110 MPa (O) | about 130 MPa (O) | about 115 MPa (O) | about 185 MPa (T5) |
| Brazeability | Excellent | Very good (watch Mg with flux) | Good | Poor in CAB (Mg) |
| Strength after brazing | Low | Moderate | Low–moderate | Lost unless re-heat-treated |
| Extrudability | Very good | Good | Good | Excellent |
| Typical automotive use | Tube, fins, lines | Radiator and heater parts | Trim, painted parts | Trim, frames, roof rails |
Choose 3003 when brazing reliability and lowest cost matter most, 3005 when a brazed or lightly loaded part needs a bit more strength, and a 6xxx alloy such as 6063 when the part is structural and will not be brazed.
How to order 3005 profiles from Metline
- SpecifyAlloy and temper (3005-H112 or O), section drawing, length or cut-part drawing, finish, quantity and annual volume.
- Confirm the standardGB/T 33910 for automotive extrusions, ASTM B221 or EN 755, plus any brazing, leak or corrosion test requirements of your programme.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your plant or port.
- Process and inspectProfiles are cut, deburred and cleaned where specified, dimensionally inspected and packed with ends protected.
- Document and shipEach lot ships with an EN 10204 3.1 mill test certificate, lot traceability and a packing list, in seaworthy export packing. Third-party inspection can be arranged on request.
References and standards
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- GB/T 33910-2017 – Aluminium and aluminium alloy extruded profiles for automobiles
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- ASTM G85 – Standard Practice for Modified Salt Spray (Fog) Testing (Annex A3, SWAAT)
- ASM Handbook Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
3005 automotive aluminium (aluminum) profiles: frequently asked questions
What does H112 mean for 3005 profiles?
H112 is the as-fabricated condition with tested mechanical properties: the profile is used as it comes off the extrusion press, without deliberate strain hardening or annealing. Its properties are close to those of the annealed O temper.
Is 3005 stronger than 3003?
Yes. The 0.2 – 0.6 % magnesium addition makes 3005 roughly 15 – 25 % stronger than 3003 in the same temper, while keeping similar corrosion resistance and formability.
Can 3005 extrusions be brazed?
Yes, with standard Al-Si fillers. Because magnesium reacts with non-corrosive fluxes, check the magnesium level against your flux system; many brazers specify the lower part of the range for controlled-atmosphere brazing.
Can 3005 be heat treated to increase strength?
No. It is non-heat-treatable. Strength comes from manganese and magnesium in the alloy and from cold work in rolled tempers; heat treatment only softens it.
Is 3005 used for exhaust pipes?
No. Exhaust gas temperatures are far beyond what aluminium alloys tolerate. 3005 tube is used on the coolant, oil and air-conditioning side of the vehicle.
Do you ship 3005 profiles internationally?
Yes. Metline supplies 3005 extrusions worldwide from Mumbai with EN 10204 3.1 certificates and export packing, on EXW, FOB, CIF or DAP terms.
Need 3005 profiles or tube for a cooling system?
Send the drawing, temper, length and annual volume. Our team will reply with feasibility, certification and a delivered price.
