O
For deep drawing, spinning and stretch forming. Parts can be formed to very tight radii and stiffen slightly as they work-harden.
Aerospace · Al-Mn sheet
3103 / 3103A Aircraft Aluminium Sheet
3103 is the European aluminium-manganese sheet alloy, a close relative of 3003, used in aircraft for formed, lightly loaded parts such as fairings, ducting, tanks and heat-exchanger components. It is non-heat-treatable, forms and welds easily and resists corrosion well. Metline supplies 3103 and 3103A sheet to EN 485 and British aerospace specifications, worldwide.
- Alloy
- EN AW-3103 / 3103A (AlMn1)
- Tempers
- O, H12, H14, H16, H18, H2x
- Standards
- EN 485 · EN 573-3 · BS L59/L60/L61
- Thickness
- 0.5 – 6 mm sheet; plate on request
What 3103 is, and why British and European drawings call for it
3103 (AlMn1) carries about 1 % manganese with no required copper. It is the standard Al-Mn sheet alloy in Europe, in the same way that 3003 is in North America.
Like every 3xxx alloy, 3103 gains strength only from cold work. It is supplied annealed (O) for heavy forming, or strain-hardened to quarter, half, three-quarter or full hard. Because no solution treatment or ageing is involved, formed parts keep their properties without further heat treatment, and welding does not cause the large strength loss seen in heat-treated alloys beyond the return to annealed strength in the heat-affected zone.
British aircraft programmes adopted 3103 under the old BS 1470 designation N3 (NS3 for sheet) and the BS aerospace L-series. It remains a common choice for formed secondary parts on aircraft and helicopters designed or maintained to UK and European documentation, and for ground support equipment, ducting and heat exchangers.
3103 chemical composition (wt %)
Limits below follow EN 573-3 for EN AW-3103. 3103A is a separately registered variant with slightly different limits; a mill certificate states which one the material meets, and the two should not be swapped without the design authority agreeing.
| Element | 3103 (EN AW-3103) | 3003, for comparison |
|---|---|---|
| Silicon (Si) | ≤ 0.50 | ≤ 0.6 |
| Iron (Fe) | ≤ 0.7 | ≤ 0.7 |
| Copper (Cu) | ≤ 0.10 | 0.05 – 0.20 |
| Manganese (Mn) | 0.9 – 1.5 | 1.0 – 1.5 |
| Magnesium (Mg) | ≤ 0.30 | — |
| Chromium (Cr) | ≤ 0.10 | — |
| Zinc (Zn) | ≤ 0.20 | ≤ 0.10 |
| Zirconium + titanium (Zr + Ti) | ≤ 0.10 | — |
| Others, each / total | 0.05 / 0.15 | 0.05 / 0.15 |
| Aluminium (Al) | Remainder | Remainder |
The practical differences are small: 3103 allows a little magnesium and no minimum copper, while 3003 requires 0.05 % copper. Strength and formability are essentially the same, which is why most non-critical applications treat them as alternatives.
3103 sheet properties by temper
Values below are the EN 485-2 tensile limits for 3103 sheet in mid thickness bands (roughly 0.5 – 3 mm). Limits shift slightly with thickness, and the governing specification on your order always takes precedence.
| Temper | Condition | Tensile Rm (MPa) | Proof Rp0.2 min (MPa) |
|---|---|---|---|
| O / H111 | Annealed | 90 – 130 | 35 |
| H12 | Quarter hard | 115 – 155 | 85 |
| H14 | Half hard | 140 – 180 | 120 |
| H16 | Three-quarter hard | 160 – 200 | 145 |
| H18 | Full hard | 185 min | 165 |
| H22 | Quarter hard, partially annealed | 115 – 155 | 80 |
| H24 | Half hard, partially annealed | 140 – 180 | 110 |
| H26 | Three-quarter hard, partially annealed | 160 – 200 | 135 |
Physical properties (typical)
- Density
- 2.73 g/cm³
- Melting range
- about 640 – 655 °C
- Modulus of elasticity
- about 69 GPa
- Thermal conductivity
- about 155 – 190 W/m·K depending on temper
- Thermal expansion
- about 23 µm/m·°C (20 – 100 °C)
Some older data sheets for this product mix up the rows of the property table, listing elongation in MPa and shear strength in per cent. The values above are arranged correctly.
Which 3103 temper to order
H14
The most commonly ordered temper. Stiff enough for panels and covers while still bending well in thin gauges.
H12 / H22
Light cold work for parts that need a little more stiffness than O but still see heavy forming. Associated with the BS L60 sheet document.
H16 / H26
Higher strength for flat or lightly formed parts that must resist denting. Associated with the BS L59 sheet document.
H18
Full hard, for flat parts, fins and feedstock that will not be bent much.
H2x vs H1x
H2x tempers reach the same strength band with more elongation, so they tolerate bending after blanking better than the matching H1x temper.
3103 standards and equivalent designations
The British aerospace sheet documents for 3103 are the L-series: BS L59, BS L60 and BS L61, which cover 3103 sheet in different temper conditions (harder, half-hard and annealed respectively). Always check the current issue of the document named on the drawing to confirm the exact temper and test requirements before ordering.
| System | Designation | Document |
|---|---|---|
| European | EN AW-3103 / EN AW-AlMn1 | EN 573-3, EN 485-1/-2/-4 |
| European variant | EN AW-3103A | EN 573-3 |
| British aerospace | 3103 sheet, by temper | BS L59, BS L60, BS L61 |
| British (legacy general) | N3 / NS3 | BS 1470 (withdrawn, replaced by EN 485) |
| German Werkstoff | 3.0515 (AlMn1) | DIN EN 485 |
| ISO | AlMn1 | ISO 209, ISO 6361 |
| North American near-equivalent | 3003 | ASTM B209 (not identical; confirm before substituting) |
Sizes and weights
3103 / 3103A supply range
- Thickness
- 0.5 – 6 mm sheet; thicker plate in H112 or O on request
- Sheet sizes
- 1000 × 2000, 1250 × 2500, 1500 × 3000 mm; cut blanks to drawing
- Coil and strip
- Slit strip for fins, tube stock and formed parts
- Tempers
- O, H12, H14, H16, H18, H22, H24, H26
- Surface
- Mill finish; PVC film, paper interleaving or pre-painted on request
H14 is the most commonly stocked temper; others are ordered to requirement.
At 2.73 g/cm³, 3103 sheet weighs 2.73 kg/m² per millimetre of thickness.
| Thickness (mm) | kg/m² | 1000 × 2000 mm sheet (kg) | 1250 × 2500 mm sheet (kg) |
|---|---|---|---|
| 0.5 | 1.36 | 2.7 | 4.3 |
| 0.8 | 2.18 | 4.4 | 6.8 |
| 1 | 2.73 | 5.5 | 8.5 |
| 1.2 | 3.28 | 6.6 | 10.2 |
| 1.5 | 4.09 | 8.2 | 12.8 |
| 2 | 5.46 | 10.9 | 17.1 |
| 2.5 | 6.83 | 13.7 | 21.3 |
| 3 | 8.19 | 16.4 | 25.6 |
| 4 | 10.92 | 21.8 | 34.1 |
| 5 | 13.65 | 27.3 | 42.7 |
| 6 | 16.38 | 32.8 | 51.2 |
| 8 | 21.84 | 43.7 | 68.2 |
| 10 | 27.30 | 54.6 | 85.3 |
| 12 | 32.76 | 65.5 | 102.4 |
| 16 | 43.68 | 87.4 | 136.5 |
Forming, joining and finishing
Forming
Excellent in O and H2x. Anneal at roughly 350 – 410 °C to restore ductility between deep-draw stages.
Welding
TIG and MIG with 4043A or 1050A filler. The HAZ returns to annealed strength, so design H14 welded parts to O values near the weld.
Brazing
Very good; 3103 and 3003 are the usual cores for clad brazing sheet in radiators and heat exchangers.
Machining
Soft and gummy in O; H14 and harder tempers machine more cleanly with sharp, polished tools.
Finishing
Accepts conversion coating, primer and paint; anodising gives a slightly grey film.
Corrosion
Very good in atmosphere and fresh water; no stress-corrosion or exfoliation problems.
Where 3103 sheet is used in aerospace
- Fairings and closures: formed covers, trailing-edge closures and access-panel skins that carry no primary load
- Ducting: air-conditioning, ventilation and avionics-cooling ducts and transitions
- Tanks and containers: water and fluid reservoirs, drip trays and covers
- Heat exchangers: fins, tube stock and headers in oil and air coolers
- Interior parts: galley and cabin panels, trims and closeouts
- Ground equipment: panels, steps, guards and enclosures for tugs, carts and maintenance stands
Primary structure such as skins, frames and fittings uses heat-treatable alloys. Where a formed part needs more strength or better fatigue performance than 3103 offers, 5251 or 5052 is the usual next step.
How to order 3103 sheet
- SpecifyAlloy and temper, thickness, sheet size or blank drawing, quantity and the governing specification with its revision (EN 485 with EN 573-3 chemistry, BS L59 / L60 / L61, or your OEM document).
- ConfirmWe confirm the specification can be met, the tolerance class, test requirements and delivery terms (EXW, FOB, CIF or DAP).
- InspectMaterial is checked for dimensions and surface condition; any extra tests named on the order are carried out or arranged.
- 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 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
- EN 485-2 – Aluminium and aluminium alloys: sheet, strip and plate, mechanical properties
- EN 485-4 – Aluminium and aluminium alloys: sheet, strip and plate, tolerances on shape and dimensions for cold-rolled products
- BS L59, L60, L61 – Aerospace series: aluminium alloy 3103 sheet (British Standards Institution)
- ASM Handbook, Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
3103 aircraft aluminium (aluminum) sheet: buyer questions
Is 3103 the same as 3003?
Not exactly, but very close. 3103 allows up to 0.30 % magnesium and has no minimum copper; 3003 requires 0.05 – 0.20 % copper. Strength and formability are almost identical, so they are alternatives for most non-critical parts once the design authority agrees.
What is the difference between 3103 and 3103A?
3103A is a separately registered variant in EN 573-3 with slightly different composition limits. Order the one your drawing names; the certificate will state which it is.
Can 3103 sheet be heat-treated to T4 or T6?
No. It is non-heat-treatable. Strength comes only from cold work (H tempers), and annealing gives the O temper.
Which temper is best for deep drawing?
O temper. If the part needs more stiffness after forming but must still bend well, H22 or H24 is a good compromise.
What does the BS L-series cover?
BS L59, L60 and L61 are British aerospace sheet documents for 3103 in different temper conditions. Check the issue named on your drawing for the exact temper and test requirements.
Do you ship 3103 sheet worldwide?
Yes. Metline supplies 3103 and 3103A sheet from Mumbai to customers worldwide, with EN 10204 3.1 certificates and export packing.
Need 3103 sheet for an aircraft or ground-equipment part?
Send the temper, thickness, size, quantity and specification. We will confirm availability and certification.
