O (annealed)
Softest condition, used for cold heading and heavy forming before heat treatment.
High-strength 6xxx aerospace wire
6056 Aerospace Aluminium Wire
6056 is one of the strongest 6xxx aluminium alloys: silicon, magnesium, copper, manganese and a little zinc give it peak-aged strength well above 6061, while keeping weldability and a lower density than 2xxx aircraft alloys. Metline supplies 6056 wire and drawn rod in O, T4 and T6 tempers for aerospace fasteners, pins and machined parts, to customers worldwide.
- Alloy
- EN AW-6056 (AlSi1MgCuMn)
- Tempers
- O, T4, T6
- Form
- Wire and drawn rod
- Use
- Fasteners, pins, small parts
What is 6056 aluminium wire?
6056 is a European-developed Al-Si-Mg-Cu alloy. It was introduced for aircraft fuselage sheet and extruded stringers as a lighter, weldable alternative to 2024, and it is the alloy used with 6013 for laser-welded stringer panels on some modern airliners. Drawn into wire and rod, the same chemistry gives a high-strength 6xxx feedstock for cold-headed and machined parts.
Compared with 6061, 6056 contains more silicon, more copper and a deliberate manganese addition. The extra silicon and copper raise the amount of strengthening precipitate formed during ageing, so 6056-T6 is clearly stronger than 6061-T6. Manganese and zirconium control the grain structure, which keeps toughness acceptable at this strength.
The price of the extra copper is a known sensitivity to intergranular corrosion in the peak-aged T6 condition. For sheet that will see moisture, airframe makers use an over-aged temper (T78) that restores corrosion resistance at a small loss of strength. For wire and fasteners, the normal answer is a protective finish such as anodising or a conversion coating, plus a sealant on installation.
6056 chemical composition (wt %)
Limits below are the registered values for EN AW-6056 (Aluminum Association 6056). The mill certificate reports the actual analysis of each cast.
| Element | Minimum | Maximum | Role in the alloy |
|---|---|---|---|
| Silicon (Si) | 0.7 | 1.3 | Excess silicon above the Mg2Si balance raises strength |
| Iron (Fe) | — | 0.50 | Impurity |
| Copper (Cu) | 0.50 | 1.1 | Adds strength; increases intergranular corrosion sensitivity |
| Manganese (Mn) | 0.40 | 1.0 | Grain structure control, toughness |
| Magnesium (Mg) | 0.6 | 1.2 | Forms strengthening precipitates with silicon |
| Chromium (Cr) | — | 0.25 | Grain control |
| Zinc (Zn) | 0.10 | 0.7 | Small strength contribution |
| Titanium + Zirconium | — | 0.20 | Grain refinement |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder |
6056 tempers for wire and rod
T4
Solution heat-treated and naturally aged. Good ductility with moderate strength; parts can be formed and then artificially aged.
T6
Solution heat-treated and artificially aged to peak strength. The usual finished condition for pins, fasteners and machined parts.
Over-aged (T7x / T78)
Aged beyond peak to improve intergranular corrosion resistance. Common for sheet; available for wire and rod on request.
Peak-aged 6056 reaches a tensile strength noticeably higher than 6061-T6, and closer to the 2xxx alloys than any common 6xxx grade. Exact minimum values depend on the specification, diameter and temper. Some published tables quote very high minimums for 6056 wire (above 500 MPa); these are not consistent with the alloy and should not be used for design. Design to the guaranteed values on your order specification and the mill certificate.
Physical properties (typical)
- Density
- About 2.71 – 2.72 g/cm³
- Modulus of elasticity
- About 70 GPa
- Melting range
- About 570 – 645 °C
- Coefficient of thermal expansion
- About 23 µm/m·°C (20 – 100 °C)
6056 wire and rod supply range
Supply range
- Diameter
- Wire from about 1 mm; drawn and extruded rod up to about 50 mm
- Form
- Coils, spools or straight cut lengths
- Tempers
- O, T4, T6, or over-aged tempers as specified
- Standards
- EN 573-3 chemistry; mechanical properties to customer, OEM or EN aerospace specifications
- Testing
- Chemistry, tensile, hardness; intergranular corrosion and heading tests on request
Tell us the governing specification. 6056 wire is often ordered to an airframe or fastener maker's own material specification.
Heading, machining, welding and finishing
Cold heading
Head in O or freshly quenched condition, then age to T6. Heading performance is lower than 6053 or 1100, so check the heading ratio with a trial.
Machining
Machines well in T6 with short chips and a good finish; similar to 6061 practice with sharp carbide tools.
Welding
Weldable by laser, TIG and MIG, which is one of its advantages over 2024. Filler choice (4xxx) is set by the welding procedure.
Corrosion protection
Anodise, apply a chromate-free conversion coating or prime parts. Avoid leaving peak-aged parts bare in wet service.
Where 6056 wire is used
- Fasteners and pins where a stronger 6xxx alloy is wanted instead of a copper-rich 2xxx rivet alloy
- Turned and machined parts cut from drawn rod: bushes, spacers, fittings and small brackets
- Welded wire assemblies where 2xxx alloys would crack during welding
- Space and satellite hardware needing a strong, weldable, low-density alloy
- Instrument and equipment parts in aerospace ground and cabin systems
6056 is not a conductor alloy: its high alloy content gives much lower electrical conductivity than 6101 or 1350. For conductors, choose those alloys instead.
6056 compared with 6061, 6013 and 2024
| Property | 6061-T6 | 6013-T6 | 6056-T6 | 2024-T4 |
|---|---|---|---|---|
| Relative strength | Moderate | High for 6xxx | High for 6xxx | High |
| Weldability | Good | Good | Good | Poor |
| Intergranular corrosion (peak aged) | Low risk | Some risk | Known risk | Higher risk |
| Density | 2.70 | About 2.71 | About 2.72 | 2.78 |
| Main aerospace use | General parts, tube, fittings | Fuselage sheet | Fuselage sheet, stringers, parts | Skins, rivets, fittings |
How to order 6056 wire
- SpecifyAlloy and temper, wire or rod diameter, coil or length format, quantity and the governing specification with its revision (an OEM or EN aerospace material specification).
- ConfirmWe confirm the specification can be met, the tolerance class, any extra tests and the delivery terms (EXW, FOB, CIF or DAP).
- InspectMaterial is checked for dimensions, surface condition and identification; tests named on the order are carried out or arranged with a third party.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing chemistry and mechanical results, traceable to the cast or lot number.
- Pack and shipExport packing in sealed, moisture-protected wooden cases or on pallets, shipped by sea or air to your port or door.
References and standards
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- ASM International – 6056: Extrusion and Sheet Alloy (ASM Handbook data)
- ASM Handbook, Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
6056 aluminium (aluminum) wire: frequently asked questions
How strong is 6056 compared with 6061?
6056-T6 is clearly stronger than 6061-T6 because it contains more silicon and copper. It is among the strongest 6xxx alloys, though still below 2024 and 7075.
Is 6056 prone to corrosion?
In the peak-aged T6 condition it can suffer intergranular corrosion in wet, salty environments. Over-ageing (as in the T78 sheet temper) or a protective finish such as anodising or a conversion coating controls this.
Can 6056 be welded?
Yes. It is weldable by laser, TIG and MIG, which is why it is used for laser-welded fuselage panels. Most high-strength 2xxx and 7xxx alloys cannot be welded this way.
Which standards cover 6056 wire?
Chemistry is defined in EN 573-3 (EN AW-6056). Mechanical properties are usually set by the airframe or fastener maker's material specification or an EN aerospace standard named on the order.
Is 6056 used for electrical wire?
No. Its high alloy content gives low conductivity. Use 1350 or 6101 for conductors.
Can Metline supply cut lengths?
Yes. 6056 rod and wire can be supplied in coils or straightened and cut to length, with mill test certificates, to customers worldwide.
Need 6056 wire or rod?
Send the diameter, temper, quantity and specification. Our team will confirm availability, testing and a delivered price.
