Aircraft structure
Solid rivets in wing and fuselage joints where high shear load is carried, and where icebox rivets are impractical.
Fastener wire guide
7xxx Series Aluminium Rivet Wire: 7075, 7050 and 7A03
7xxx rivet wire is the drawn Al-Zn-Mg-Cu wire that rivet and fastener makers cold-head into the strongest aluminium rivets in common use. 7050-T73 is the standard Western choice for high-shear aerospace rivets, 7075 serves pins, lockbolt collars and screw-type fasteners, and the GB grades 7A03, 7A04 and 7A09 cover the same roles under Chinese and related specifications. This guide compares the grades and explains what to specify.
- Grades
- 7050, 7075, 7A03, 7A04, 7A09
- Delivery tempers
- O, H13, H14, H18, T6
- Diameter
- About 1.6 – 15 mm
- Standards
- EN 3115 · ASTM B316 · GB/T 3195
Why use 7xxx wire for rivets?
A solid rivet is only as strong as the shear strength of its shank. The common aerospace rivet alloys form a ladder: 1100 at the bottom, then 5056, 2117, 2017 and 2024, with 7050-T73 among the highest-shear aluminium rivets in routine production at about 41 ksi (283 MPa) minimum shear.
What makes 7050 attractive is not only strength. 2024-T4 "icebox" rivets reach similar shear strength, but they must be solution treated and then kept refrigerated and driven within a short time, because they age-harden at room temperature and become too hard to upset. A 7050-T73 rivet is driven in the as-received, fully treated condition, so it removes the refrigeration and logistics problem while also offering better stress-corrosion resistance thanks to the over-aged T73 temper.
For other fasteners, such as hollow pins, threaded inserts, lockbolt collars, screw rivets and blind-rivet mandrels, 7075 and the GB grades are used where high hardness and tensile strength matter more than upsetting ductility. In every case the wire maker supplies the alloy in a soft or lightly drawn temper for heading, and the fastener manufacturer heat-treats the finished part.
Which 7xxx grade does what
| Grade | System | Typical fastener use | Notes |
|---|---|---|---|
| 7050 | AA / EN / AMS | Solid aerospace rivets driven in T73 (NAS1097 KE and similar) | High Zn and Cu with Zr instead of Cr; good toughness and SCC resistance in T73 |
| 7075 | AA / EN / AMS | Pins, collars, screw-type and special fasteners; some rivets in T73 | Higher strength in T6 but more sensitive to stress corrosion; T73 trades strength for SCC resistance |
| 7003 | AA / EN | Medium-strength fasteners and formed parts | Leaner Cu-free composition, weldable, easier to work |
| 7A03 | GB (China) | High-strength rivets and screw rivets, typically headed in H14 and used in T6 | Composition sits between 7050 and lean 7xxx; the GB counterpart to Western high-shear rivet wire |
| 7A04 | GB (China) | Screw rivets, pins and structural fasteners in T6 | High-strength grade similar in role to 7075 |
| 7A09 | GB (China) | Rivets and pins requiring high strength with improved toughness | Close to 7075 in composition |
If your drawings follow Western aerospace standards, the safe choice is 7050 for solid rivets and 7075 for other parts. GB grades are typically specified by fastener makers serving Chinese aircraft programmes or domestic machinery, and they should only be substituted after a formal equivalence review.
Composition limits (wt %)
| Element | 7050 | 7075 | 7003 | 7A03 | 7A04 | 7A09 |
|---|---|---|---|---|---|---|
| Zn | 5.7 – 6.7 | 5.1 – 6.1 | 5.0 – 6.5 | 6.0 – 6.7 | 5.0 – 7.0 | 5.1 – 6.1 |
| Mg | 1.9 – 2.6 | 2.1 – 2.9 | 0.50 – 1.0 | 1.2 – 1.6 | 1.8 – 2.8 | 2.0 – 3.0 |
| Cu | 2.0 – 2.6 | 1.2 – 2.0 | 0.20 | 1.8 – 2.4 | 1.4 – 2.0 | 1.2 – 2.0 |
| Cr | 0.04 | 0.18 – 0.28 | 0.20 | 0.05 | 0.10 – 0.25 | 0.16 – 0.30 |
| Zr | 0.08 – 0.15 | — | 0.05 – 0.25 | — | — | — |
| Mn | 0.10 | 0.30 | 0.30 | 0.10 | 0.20 – 0.60 | 0.15 |
| Si | 0.12 | 0.40 | 0.30 | 0.20 | 0.50 | 0.50 |
| Fe | 0.15 | 0.50 | 0.35 | 0.20 | 0.50 | 0.50 |
Single values are maxima. Western grades per the Aluminum Association / EN 573-3; GB grades per GB/T 3190. Small Ti additions and others limits are omitted for clarity; the certificate reports the full analysis.
Note the low iron and silicon in 7050. Fewer coarse Fe- and Si-rich particles mean better toughness and cleaner cold heading, which reduces cracking in the rivet head. Zirconium in 7050 controls grain structure without the quench sensitivity that chromium brings, which matters for thicker wire and bar.
Delivery tempers and final properties
Rivet wire is bought in a condition suited to heading, not in the final service temper. The fastener maker forms the head and then heat-treats, or in the case of 7050-T73 rivets the wire maker or rivet maker treats the wire before heading according to the process route.
| Temper | Condition | Typical use |
|---|---|---|
| O | Fully annealed, softest | Severe heading; part heat-treated afterwards |
| H13 / H14 | Lightly drawn for straightness and size control | Most cold-heading lines; best balance of formability and handling |
| H18 | Heavily drawn | Straight lengths and pins that are machined rather than headed |
| T6 | Solution treated and peak aged | Pins and parts used as-drawn; highest strength, lowest SCC resistance |
| T73 | Solution treated and over-aged | 7050 solid rivets and SCC-critical fasteners |
Indicative strength in final temper
- 7050-T73 solid rivet
- Shear strength about 41 ksi (283 MPa) minimum
- 7075-T6 (typical, bar and wire)
- Tensile about 570 MPa, yield about 500 MPa, shear about 330 MPa
- 7075-T73 (typical)
- Tensile about 505 MPa, yield about 435 MPa
- Annealed wire, O temper
- Tensile normally no more than about 275 MPa, which is what makes heading possible
Typical values per ASM data; design minimums come from the governing fastener specification and MMPDS.
Diameter tolerance, surface and testing
Cold heading punishes inconsistency. A wire that is oversize by a few hundredths of a millimetre will jam in the die; an undersize wire leaves an underfilled head. Rivet wire standards therefore define several tolerance classes, from one-sided minus tolerances for precision dies to wider plus-minus bands for general parts, typically in the range of about 0.015 mm on small diameters to about 0.06 mm near 10 mm.
- Surface: no cracks, laps, seams, blisters, inclusions or corrosion; light handling marks only if shallower than half the minus tolerance
- Heading test: a sample is upset to a set ratio of height to diameter (often 1.2 – 1.4 × d depending on alloy and size) without cracking
- Shear test: double-shear testing of heat-treated samples confirms rivet shear strength
- Microstructure: grain size and absence of coarse recrystallisation or overheating for aerospace wire
- Coils: level-wound coils of consistent weight with clearly tagged lot numbers for traceability
Where 7xxx rivet wire ends up
Helicopters and UAVs
High-strength rivets and pins in airframes where every gram counts.
Blind and structural rivets
7xxx mandrels and sleeves in blind fasteners for transport, rail and industrial assemblies.
Motorsport and defence
Pins, collars and special fasteners for light, highly loaded structures.
Sports equipment
Bicycle, climbing and outdoor gear fasteners where strength-to-weight drives the design.
Machinery
Screw rivets and pins in equipment where steel would add weight or cause galvanic issues with aluminium.
What to check before you buy
- SpecificationName the governing standard (e.g. EN 3115 for 7050-T73 rivet wire, ASTM B316, a customer or AMS spec, or GB/T 3195).
- Grade and temperState the alloy, delivery temper and, if relevant, the final heat treatment the wire must respond to.
- SizeDiameter, tolerance class, coil weight and coil dimensions, or straight lengths.
- TestingHeading, shear and tensile tests required on each lot, plus any microstructure check.
- Documents and packingEN 10204 3.1 certificate with chemistry and test results; coils sealed against moisture in export cases.
Mixing up grades is a real risk on a heading line, since 7xxx wire looks identical to 2xxx and 5xxx wire. Insist on clear lot tags on every coil and keep certificates linked to production batches.
References and standards
- EN 3115 – Aerospace series: aluminium alloy 7050-T73 wire for solid rivets
- ASTM B316/B316M – Aluminum and Aluminum-Alloy Rivet and Cold-Heading Wire and Rods
- GB/T 3195 – Aluminium and aluminium alloy wire for rivets
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
- MMPDS – Metallic Materials Properties Development and Standardization (fastener allowables)
7xxx aluminium (aluminum) rivet wire: FAQs
Why is 7050-T73 used instead of 2024 icebox rivets?
Both give high shear strength, but 2024-T4 rivets must be solution treated and kept refrigerated until driven. 7050-T73 rivets are driven as received, avoiding that handling, and the over-aged temper gives better stress-corrosion resistance.
Can 7075 wire replace 7050 for solid rivets?
Not without engineering approval. 7075 is used for some rivets in T73, but 7050 was developed for this job and has the qualified specifications and allowables. Use 7075 where the drawing calls for it, mainly in pins, collars and machined fasteners.
What temper should rivet wire be delivered in?
Usually O or a light drawn temper such as H13 or H14, which keeps the wire soft enough to head while giving accurate size and straightness. The finished fastener is then heat-treated to T6 or T73.
Is 7A03 the same as 7050?
No. 7A03 is a GB grade with a lower magnesium range and slightly different copper and zinc limits. It fills a similar role in Chinese specifications, but it is not a direct equivalent and should not be substituted on Western-standard drawings.
Which diameters are available?
Rivet wire is typically supplied from about 1.6 mm up to around 10 mm, with some grades and fastener types going to 15 mm or more as drawn rod. Tell us the diameter and tolerance class your dies need.
Do you supply certificates for aerospace rivet wire?
Yes. Each lot ships with an EN 10204 3.1 mill certificate showing chemistry and mechanical or heading test results, and lots are tagged for full traceability.
Need 7xxx rivet wire for your heading line?
Tell us the grade, temper, diameter and specification. We will confirm availability, testing and a delivered price.
