Diameter tolerance
Heading wire is drawn to close tolerance, commonly within a few hundredths of a millimetre, so that blank volume and head fill are consistent.
Rivet wire guide
6000 Series Aluminium Wire Rod for Rivets and Cold-Headed Fasteners
6000 series (Al-Mg-Si) wire is the heat-treatable choice for rivets, screws, sleeve nuts and small cold-headed parts that need more strength than 5xxx wire but better corrosion resistance than copper-bearing 2xxx grades. It is headed soft, in the O or T4 condition, and then artificially aged to T6 so the finished fastener reaches full strength. This guide compares the common grades, explains the process route and lists what to specify.
- Alloy family
- Al-Mg-Si (6xxx)
- Common grades
- 6061 · 6082 · 6056 · 6053
- Diameter
- about 1 – 30 mm
- Route
- Head in O/T4, age to T6
Why use 6000 series wire for fasteners?
Aluminium fasteners fall into three broad groups. Pure aluminium and 5xxx alloys head easily and resist corrosion but are relatively weak. 2xxx and 7xxx alloys give the highest shear strength but contain copper, need careful heat treatment and are less corrosion-resistant. The 6xxx family sits between them.
Magnesium and silicon form Mg2Si precipitates during ageing, giving 6061-T6 a typical shear strength of about 207 MPa (30 ksi), well above 5052 and approaching 2117 rivet levels, while keeping the good general corrosion resistance and anodising response of 6xxx extrusions. The alloys are also cheap, widely produced and easy to recycle with 6xxx scrap.
That combination has made 6xxx wire the basis of a growing range of fasteners: blind and solid rivets for vehicle bodies and trailers, screws and bolts that join aluminium or magnesium castings without the galvanic problems of steel, sleeve nuts and rivet nuts, electrical connector pins and cold-headed small parts that replace machined components.
Common 6000 series grades for wire and rod
| Grade | Character | Typical fastener use |
|---|---|---|
| 6053 | Low-copper Al-Mg-Si registered for rivet wire | Rivets for joining magnesium and Al-Mg sheet, where copper must be avoided |
| 6061 | The standard structural 6xxx alloy; Cu and Cr additions | Solid and blind rivets, screws, bolts and pins; listed in ASTM B316 |
| 6082 | Higher Si and Mn; slightly stronger than 6061 | European cold-headed screws, rivet nuts and pins |
| 6056 | High-strength Al-Mg-Si-Cu | Automotive aluminium bolts and sleeve nuts, notably for magnesium and aluminium powertrain castings |
| 6005 / 6005A | Medium strength, good extrudability | Small screws and nuts made by cold heading |
| 6060 / 6063 | Lean alloys; easy to head, lower strength | Rivets and decorative fasteners that will be anodised |
| 6101 | Electrical-conductor alloy | Conductive rivets, pins and terminals |
| 6463 | Bright-finishing alloy | Decorative screw and rivet heads with a bright anodised finish |
For individual grades, see the 6061 rivet wire guide and the aerospace wire pages for 6056, 6053 and 6082.
Key composition ranges (wt %)
| Grade | Si | Mg | Cu | Mn | Cr |
|---|---|---|---|---|---|
| 6053 | (set by Mg ratio) | 1.1 – 1.4 | ≤ 0.10 | — | 0.15 – 0.35 |
| 6061 | 0.40 – 0.8 | 0.8 – 1.2 | 0.15 – 0.40 | ≤ 0.15 | 0.04 – 0.35 |
| 6082 | 0.7 – 1.3 | 0.6 – 1.2 | ≤ 0.10 | 0.40 – 1.0 | ≤ 0.25 |
| 6056 | 0.7 – 1.3 | 0.6 – 1.2 | 0.50 – 1.1 | 0.40 – 1.0 | ≤ 0.25 |
| 6063 | 0.20 – 0.6 | 0.45 – 0.9 | ≤ 0.10 | ≤ 0.10 | ≤ 0.10 |
| 6101 | 0.30 – 0.7 | 0.35 – 0.8 | ≤ 0.10 | ≤ 0.03 | ≤ 0.03 |
Aluminum Association / EN 573-3 limits, main elements only. 6053 limits silicon to 45 – 65 % of the magnesium content. Iron, zinc, titanium and other residuals are also controlled; the mill certificate gives the full analysis.
From wire to finished fastener: tempers and heat treatment
- Supply conditionWire is delivered annealed (O) for the most severe heading, or solution heat-treated and naturally aged (T4) for moderate upsets. T4 heads well for a few days to weeks after quenching and then gradually hardens.
- Cold headingThe wire is sheared to length and upset into heads, shanks and threads on single- or multi-blow headers. Soft wire fills complex dies and keeps tool wear low.
- Heat treatmentParts headed from O wire are solution treated and quenched; parts from T4 wire can go directly to ageing.
- Artificial ageingAgeing (typically around 160 – 180 °C for several hours) takes the parts to T6, at which point they have their full strength.
- FinishingAnodising, conversion coating or lubrication coatings as specified.
Some fasteners are headed from wire already in T6. That limits the upset ratio, but avoids heat-treatment distortion, and is used for pins and simple rivets. Agree the delivery temper with the wire supplier to match the heading sequence.
Quality requirements for cold-heading wire
Surface
No cracks, seams, laps, slivers or deep scratches; these open up during upsetting. Light oil or a heading lubricant coating is normal.
Upset test
Samples are compressed to a set fraction of their length; the outer surface must remain crack-free.
Shear and tensile
Measured on samples in the delivered and in the heat-treated temper, for example with the ASTM B565 shear method.
Grain structure
Coarse recrystallised surface grains cause orange peel and cracking on heading; mills control them through extrusion and drawing practice.
Coils
Level-wound coils, typically from about 50 kg upward, sized to the heading machine pay-off.
6000 series compared with other rivet wire families
| Family | Example | Strength | Corrosion | Heat treatment |
|---|---|---|---|---|
| 1xxx / 3xxx | 1035, 3A21 | Low | Excellent | None |
| 5xxx | 5052, 5056, 5A06 | Low – medium | Excellent | None |
| 6xxx | 6053, 6061, 6082, 6056 | Medium – high | Very good | Age to T6 |
| 2xxx | 2117, 2017, 2024 | High | Fair | Solution treat; some driven fresh or iced |
| 7xxx | 7050, 7075 | Highest | Fair – good (in T7x) | Solution treat and age |
Where 6000 series fasteners are used
- Automotive: aluminium bolts for magnesium and aluminium engine and gearbox castings, body rivets and rivet nuts
- Trailers and rail: rivets and lockbolts for aluminium body panels and floors
- Construction: rivets and screws for aluminium façades, windows and solar mounting
- Electrical: conductive pins, terminals and rivets from 6101
- Consumer goods: anodised decorative rivets and screws in furniture, luggage and electronics
References and standards
- ASTM B316 – Standard Specification for Aluminum and Aluminum-Alloy Rivet and Cold-Heading Wire and Rods
- ASTM B565 – Standard Test Method for Shear Testing of Aluminum and Aluminum-Alloy Rivets and Cold-Heading Wire and Rods
- EN 1301-1/-2/-3 – Aluminium and aluminium alloys: drawn wire (delivery conditions, mechanical properties, tolerances)
- EN 573-3 – Chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
6000 series rivet wire: frequently asked questions
Which 6000 series alloy is most used for rivets?
6061 is the most widely used, and is listed in ASTM B316 for rivet and cold-heading wire. 6053 is used where very low copper is needed, and 6082 and 6056 for higher-strength European and automotive fasteners.
In what temper should 6xxx heading wire be bought?
O for severe upsets and complex heads, then solution treatment and ageing; T4 for moderate heading followed directly by ageing to T6. Wire can also be supplied in T6 for simple pins.
Are 6061 rivets as strong as 2024 rivets?
No. 6061-T6 has a typical shear strength of about 207 MPa, compared with about 283 MPa for 2024-T4. 6061 is chosen for better corrosion resistance and simpler handling.
Can aluminum bolts replace steel bolts on magnesium castings?
Yes, that is a major use of 6056 and similar high-strength 6xxx alloys. Aluminium bolts avoid the severe galvanic corrosion steel causes in magnesium and match its thermal expansion more closely.
What diameters are available?
Rivet and heading wire typically ranges from about 1 mm to 10 mm, with rod up to about 30 mm for larger cold-headed parts. Tolerance and coil size are agreed per order.
Need 6000 series heading wire?
Send grade, temper, diameter and quantity. Metline will confirm availability, certificates and delivered pricing worldwide.
