Heading
5056 work-hardens faster than 5052, so dies wear more and heavy upsets may need two stages. Good lubrication and burr-free cut-off are essential.
Rivet wire guide
5056 / 5056A Aluminium Rivet Wire
5056 rivet wire is a 5% magnesium aluminium wire, supplied annealed for cold heading, that produces the strongest of the non-heat-treatable aluminium rivets. It is the standard rivet alloy for joining magnesium structures, is widely used for zip fasteners and marine rivets, and needs no heat treatment before driving. Metline supplies 5056 and the European 5056A (now EN AW-5019) chemistry from 1.6 to 10 mm, with certificates, worldwide.
- Alloys
- 5056 · 5056A (EN AW-5019)
- Temper
- O for heading; rivets often H32
- Diameter
- 1.6 – 10 mm
- Standards
- ASTM B316 · EN 1301 · GB/T 3195
What makes 5056 a rivet alloy?
Most aluminium rivets fall into two groups: heat-treatable 2xxx rivets, which are strong but must be driven within a short time after solution treatment, and non-heat-treatable rivets in 1xxx, 3xxx and 5xxx alloys, which can be stored indefinitely. 5056 is the strongest member of the second group.
Its high magnesium content gives annealed wire that is still soft enough to head, yet the cold work of heading raises the rivet to a useful shear strength. In US military and aerospace fastener standards, 5056 rivets carry the material code B (for example MS20470B and MS20426B) and are supplied in the H32 condition, with a design shear strength of about 193 MPa (28 ksi), close to that of 2117-T4 "AD" rivets.
The main reason 5056 rivets exist, however, is galvanic compatibility. Magnesium alloys corrode rapidly when joined with copper-bearing 2xxx rivets; 5056 is close enough to magnesium in the galvanic series to be the specified rivet for magnesium parts in aircraft, helicopters and electronics housings.
5056 and 5056A chemical composition (wt %)
5056 is the Aluminum Association / ASTM designation. 5056A is the older European designation for a closely related AlMg5 chemistry that EN 573-3 now registers as EN AW-5019. The main difference is that 5019 allows more manganese and iron. Confirm on your order which one your drawing calls for.
| Element | 5056 (UNS A95056) | EN AW-5019 (ex 5056A) |
|---|---|---|
| Magnesium (Mg) | 4.5 – 5.6 | 4.5 – 5.6 |
| Manganese (Mn) | 0.05 – 0.20 | 0.10 – 0.6 |
| Chromium (Cr) | 0.05 – 0.20 | 0.20 max |
| Silicon (Si) | 0.30 max | 0.40 max |
| Iron (Fe) | 0.40 max | 0.50 max |
| Copper (Cu) | 0.10 max | 0.10 max |
| Zinc (Zn) | 0.10 max | 0.20 max |
| Titanium (Ti) | — | 0.20 max |
| Others, each / total | 0.05 / 0.15 | 0.05 / 0.15 |
| Aluminium (Al) | Remainder | Remainder |
5019 limits as commonly listed from EN 573-3; the certificate for each lot gives the governing values.
Mechanical properties
Rivet wire standards set a maximum tensile strength for O-temper wire so that it heads without splitting. For 5056-O this cap is about 320 MPa (46 ksi). Typical values and the strength of driven rivets are shown for reference.
| Condition | Tensile strength | Yield strength | Elongation | Shear strength |
|---|---|---|---|---|
| 5056-O wire, specified | ≤ 320 MPa (max) | — | — | — |
| 5056-O, typical | 290 MPa | 150 MPa | 35 % | 180 MPa |
| 5056-H32 rivet, design value | — | — | — | ≈ 193 MPa (28 ksi) |
| 5056-H38, typical | 415 MPa | 345 MPa | 15 % | 234 MPa |
Physical data
- Density
- 2.64 g/cm³
- Melting range
- 568 – 638 °C
- Modulus of elasticity
- about 71 GPa
- Electrical conductivity
- about 29 % IACS (O temper)
Supply range and diameter tolerances
Supply range
- Diameter
- 1.6 – 10.0 mm; imperial sizes such as 3/32, 1/8, 5/32 and 3/16 in on request
- Temper
- O (annealed); H32 or other tempers on request
- Form
- Coils, spools or straight lengths
- Surface
- Bright and clean, free of cracks, seams, laps, scratches, oil stains and corrosion
| Diameter (mm) | Class A | Class B | Class C | Class D |
|---|---|---|---|---|
| > 1.6 – 4.0 | +0 / −0.025 | +0.025 / −0.015 | ±0.025 | +0 / −0.05 |
| > 4.0 – 6.0 | +0 / −0.030 | +0.025 / −0.025 | ±0.040 | +0 / −0.08 |
| > 6.0 – 10.0 | +0 / −0.040 | +0.050 / −0.025 | ±0.060 | +0 / −0.12 |
Tolerance classes as commonly used for drawn rivet wire (GB/T 3195). ASTM B316 and EN 1301-3 tolerances are supplied when ordered to those standards.
Heading, driving and service limits
Driving
Rivets can be driven as received at any time; there is no ageing clock as there is with 2017 or 2024 rivets.
Magnesium structures
Use 5056 rivets, ideally wet-installed with sealant, for magnesium skins and castings to minimise galvanic attack.
Temperature limit
With more than 3 % magnesium, 5056 can become sensitised after long exposure above about 65 °C, making it prone to intergranular and stress corrosion. Use 5052 or 2117 rivets for warm service.
Corrosion
Very good resistance to seawater and marine air at normal temperatures; widely used for marine and coastal riveting.
Finishing
Rivets can be anodised or chemically coated; aerospace rivets are often supplied with a conversion coating.
Where 5056 rivet wire is used
- Aerospace: "B" code rivets for magnesium parts and for secondary structures
- Zip fasteners: 5056 wire is rolled into the teeth of metal zips
- Marine: riveted fittings, trim and structures in 5xxx alloys
- Rail and road transport: body panels and interior structures
- Electronics: housings and chassis made from magnesium or aluminium
- Blind rivets: high-strength aluminium blind rivet bodies
5056 or 5052 rivet wire?
| Factor | 5056 | 5052 |
|---|---|---|
| Magnesium | 4.5 – 5.6 % | 2.2 – 2.8 % |
| Rivet strength | Higher | Medium |
| Ease of heading | Good | Very good |
| Use with magnesium | Standard choice | Less common |
| Service above 65 °C | Avoid long exposure | Suitable |
Choose 5056 for strength and magnesium compatibility; choose 5052 for easier heading and warm service. See the 5052 rivet wire guide for details.
How to order
- SpecifyAlloy (5056 or EN AW-5019), temper, diameter, tolerance class and standard (ASTM B316, EN 1301, GB/T 3195).
- Confirm limitsMaximum tensile strength, and any heading test your process needs.
- PackingCoil dimensions and weight to suit your header pay-off, with moisture-proof wrapping.
- DocumentsEN 10204 3.1 mill test certificate per lot; third-party inspection on request.
References and standards
- ASTM B316/B316M – Aluminum and Aluminum-Alloy Rivet and Cold-Heading Wire and Rods
- EN 573-3 – Chemical composition and form of wrought products
- EN 1301-2 / 1301-3 – Aluminium and aluminium alloys: drawn wire, mechanical properties and tolerances
- NASM20470 (MS20470) – Rivet, Solid, Universal Head, Aluminum Alloy
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
5056 rivet wire: frequently asked questions
What is the difference between 5056 and 5056A?
5056 is the US-registered alloy. 5056A was a European AlMg5 variant, now designated EN AW-5019, which allows higher manganese and iron. Mechanical behaviour is similar, but the two are not identical on paper, so order the one your drawing specifies.
Why are 5056 rivets used on magnesium?
Magnesium corrodes quickly next to copper-bearing aluminium alloys. 5056 contains almost no copper and sits close to magnesium in the galvanic series, which keeps galvanic corrosion low.
Does 5056 rivet wire need heat treatment?
No. It is non-heat-treatable, does not age, and can be headed and driven at any time after delivery.
What is the maximum service temperature for 5056 aluminum rivets?
For long-term service keep below about 65 °C. Above that, high-magnesium alloys can become sensitised and lose resistance to intergranular and stress corrosion.
What does the letter B mean on a rivet?
In MS/NAS rivet part numbers, B denotes 5056 aluminium alloy, supplied in H32 condition. AD is 2117-T4, D is 2017-T4 and DD is 2024-T4.
Need 5056 or 5056A rivet wire?
Tell us the alloy, diameter, tolerance and coil size. We will reply with availability, certification and a delivered price.
