H14 (half hard)
The standard rivet-wire temper. Enough cold work to give useful shear strength and a clean cut-off, while still leaving the ductility to form a full round, countersunk or flat head in one or two blows.
Rivet wire selection guide
3003, 3004 and 3A21 Aluminium Rivet Wire
3003, 3004 and 3A21 are aluminium-manganese alloys drawn into wire for cold-headed rivets that need good corrosion resistance and easy upsetting rather than high shear strength. 3003 and 3A21 are near-identical, softer grades; 3004 adds about 1 % magnesium for roughly 25 % more shear strength. This guide compares the three and explains how to specify the wire.
- Alloys
- 3003 · 3004 · 3A21
- Usual temper
- H14 (also O, H12)
- Diameter
- about 1.6 – 10 mm
- Form
- Coils or straight lengths
Where 3xxx alloys fit among rivet materials
Aluminium rivets are made from wire that is cut to length and cold headed. The alloy decides two things that pull in opposite directions: how much shear load the finished rivet carries, and how easily the head forms without cracking.
At one end sit 1xxx grades such as 1100 and 1050A, soft and very ductile but low in strength. At the other end are heat-treatable 2xxx and 7xxx grades (2017, 2117, 2024, 7050) used for aircraft structure, which need solution treatment and often have to be driven within a time limit or stored refrigerated. The 3xxx manganese alloys sit between: stronger than pure aluminium, still easy to head cold, and they need no heat treatment at any stage.
That makes 3003, 3004 and 3A21 a practical choice for brake-lining rivets, blind and tubular rivets, hardware, appliance and furniture assembly, signage, HVAC ductwork and light transport bodies: joints that are lightly or moderately loaded, often outdoors or in damp conditions, and made in high volumes on automatic heading machines.
Chemical composition of 3003, 3004 and 3A21 (wt %)
Limits for 3003 and 3004 follow the Aluminum Association registration used by ASTM and EN 573-3. 3A21 is the Chinese GB/T 3190 designation; it differs from 3003 mainly in a slightly wider manganese range and a titanium limit. Always check the mill test certificate for the actual analysis.
| Element | 3003 | 3004 | 3A21 |
|---|---|---|---|
| Silicon (Si) | ≤ 0.60 | ≤ 0.30 | ≤ 0.60 |
| Iron (Fe) | ≤ 0.70 | ≤ 0.70 | ≤ 0.70 |
| Copper (Cu) | 0.05 – 0.20 | ≤ 0.25 | ≤ 0.20 |
| Manganese (Mn) | 1.0 – 1.5 | 1.0 – 1.5 | 1.0 – 1.6 |
| Magnesium (Mg) | — | 0.8 – 1.3 | ≤ 0.05 |
| Zinc (Zn) | ≤ 0.10 | ≤ 0.25 | ≤ 0.10 |
| Titanium (Ti) | — | — | ≤ 0.15 |
| Others each / total | 0.05 / 0.15 | 0.05 / 0.15 | 0.05 / 0.10 – 0.15 |
| Aluminium | Remainder | Remainder | Remainder |
Manganese forms fine Al-Mn-Fe particles that strengthen the matrix and keep grain size small after annealing, which helps rivet heads form with a smooth surface. Magnesium in 3004 adds solid-solution strength; it also raises the work-hardening rate, so 3004 needs slightly more heading force than 3003.
Typical properties of 3xxx rivet wire
The values below are typical figures for wrought material from ASM and Aluminum Association data, not guaranteed minimums. Rivet wire is normally bought to a maximum tensile strength in H14 so that it heads reliably, plus a minimum shear strength tested to ASTM B565 or the equivalent national method.
| Alloy and temper | Tensile strength | Yield strength | Shear strength | Brinell hardness |
|---|---|---|---|---|
| 3003-O | 110 MPa | 42 MPa | 76 MPa | 28 HB |
| 3003-H12 | 130 MPa | 125 MPa | 83 MPa | 35 HB |
| 3003-H14 | 150 MPa | 145 MPa | 97 MPa | 40 HB |
| 3004-O | 180 MPa | 69 MPa | 110 MPa | 45 HB |
| 3004-H34 | 240 MPa | 200 MPa | 124 MPa | 63 HB |
3A21-H14 behaves like 3003-H14. Rivet wire standards usually cap tensile strength in H14 (for example, about 180 MPa maximum for 3A21) to stop heads splitting.
Physical properties (3003)
- Density
- 2.73 g/cm³
- Melting range
- 643 – 654 °C
- Electrical conductivity
- about 40 – 50 % IACS depending on temper
- Thermal conductivity
- about 160 – 190 W/m·K
- Modulus of elasticity
- 69 GPa
Choosing the temper: O, H12 or H14
H12 (quarter hard)
A softer option for large heads, deep tubular rivets or heading machines with limited force. Slightly lower shear strength.
O (annealed)
Maximum ductility for semi-tubular and blind rivet bodies, or for very large upset ratios. The heading operation itself work-hardens the head.
H34 for 3004
Strain hardened and stabilised. Used where the extra strength of 3004 is the reason for choosing it, but harder to head than 3003-H14.
Sizes, tolerances and packing
Typical supply
- Diameter
- about 1.6 – 10 mm for solid rivets; larger rod for heavy rivets on request
- Diameter tolerance
- commonly ±0.02 – 0.04 mm depending on size and the standard ordered
- Format
- coils (typically 50 kg and above, matched to your pay-off), or straight cut lengths
- Surface
- clean, bright, free of cracks, laps, die lines and heavy oil; light lubricant on request
- Standards
- GB/T 3195 (rivet wire), EN 573 / EN 1301 (drawn wire), ASTM B316 (rivet and cold-heading wire and rod)
- Certification
- EN 10204 3.1 mill test certificate with chemistry, tensile and shear results
Tell us the heading machine and rivet type when you enquire. Coil weight, inner diameter and winding pattern affect how well the wire feeds, and surface lubricant must suit the heading oil you use. Wire is wrapped in protective film and packed in wooden cases or on pallets for export.
Getting good heads from 3xxx wire
- Match temper to upset ratioHead volumes above roughly 2 × diameter of wire length favour H12 or O; normal round heads run well in H14.
- Specify a heading testAsk for an upset (compression) test on samples from each coil: a short length is compressed to a set fraction of its height and must show no cracks.
- Control surface defectsLongitudinal scratches and die lines open up as cracks on the head periphery. Specify a maximum defect depth, usually no more than half the diameter tolerance.
- Keep wire dryStore coils indoors and use them in the order received. Water staining between turns marks the head surface.
- Mind galvanic contactAluminium rivets in steel or copper assemblies need insulation or a coating in wet service; 3xxx alloys sit close to other aluminium alloys and pose little risk with aluminium sheet.
Typical uses of 3003, 3004 and 3A21 rivets
- Brake and clutch linings: tubular and semi-tubular rivets that hold friction material to steel shoes
- Blind rivets: rivet bodies for general fastening of sheet in buildings, signage and enclosures
- HVAC and ductwork: joining 3003 duct and housing sheet with a matching-alloy fastener
- Vehicle bodies and trailers: trim, panels and non-structural attachments
- Appliances and electronics: housings, brackets and earthing points where some conductivity helps
- Furniture, ladders and luggage: visible rivets that must resist corrosion and look clean
For aircraft, 3xxx rivets are limited to non-structural interiors and fairings; primary structure uses 2117-T4 (AD), 2017-T4 (D), 2024-T4 (DD) or 7050-T73 (E) rivets to NAS and MS standards.
3xxx rivet wire compared with 1xxx, 5xxx and 2xxx grades
| Property | 1100 / 1050A | 3003 / 3A21 | 3004 | 5056 | 2117-T4 |
|---|---|---|---|---|---|
| Typical shear strength | ~75 MPa | ~97 MPa (H14) | ~110 – 125 MPa | ~180 MPa | ~195 MPa |
| Heading ease | Excellent | Very good | Good | Good | Good (as received) |
| Heat treatment needed | No | No | No | No | Yes, at the mill |
| Corrosion resistance | Excellent | Excellent | Very good | Very good | Fair |
| Typical use | Low-load, decorative | General light fastening | Moderate loads | Magnesium, marine | Aircraft structure |
Shear figures are indicative typical values for comparison. If you need more than about 125 MPa shear without moving to a heat-treated alloy, 5052 or 5056 wire is the usual next step.
References and standards
- ASTM B316/B316M – Aluminum and Aluminum-Alloy Rivet and Cold-Heading Wire and Rods
- ASTM B565 – Shear Testing of Aluminum and Aluminum-Alloy Rivets and Cold-Heading Wire and Rods
- GB/T 3195 – Aluminium and aluminium alloy wire for rivets
- EN 573-3 – Chemical composition and form of wrought products
- ASM Handbook Vol. 2 – Properties of Wrought Aluminum and Aluminum Alloys
3xxx aluminium rivet wire: common questions
Is 3A21 the same as 3003?
For rivet purposes they are interchangeable. 3A21 is the Chinese designation with a manganese range of 1.0 – 1.6 % and a titanium limit; 3003 has 1.0 – 1.5 % manganese and a deliberate 0.05 – 0.20 % copper addition. Properties in H14 are practically the same.
Why choose 3004 over 3003 for rivets?
The magnesium in 3004 raises shear strength by roughly 20 – 30 % without heat treatment. The trade-off is slightly harder heading and a little lower ductility.
What temper should aluminium rivet wire be?
H14 is the usual temper for solid rivets. Choose H12 or O for large upsets, tubular and blind rivet bodies, or low-force heading machines.
Can 3003 rivets be used outdoors?
Yes. 3xxx alloys have excellent atmospheric corrosion resistance and are compatible with most aluminium sheet. Insulate them from steel or copper in wet service to avoid galvanic attack.
Are 3003 rivets strong enough for aircraft?
Only for non-structural parts such as interior fittings. Primary aircraft structure uses heat-treatable rivet alloys such as 2117-T4 or 7050-T73.
What documents come with the wire?
An EN 10204 3.1 mill test certificate showing chemistry, tensile strength and, where ordered, shear and upset test results for each lot.
Need 3xxx aluminium rivet wire?
Tell us the alloy, temper, diameter, coil size and heading process. We will confirm a suitable grade, certification and delivery to your plant.
