Welding
TIG and MIG weld well with 5xxx fillers such as ER5356 or ER5183. Weld zones soften towards O-temper strength.
GB-standard Al-Mg plate
5A03 Aluminium Plate & Sheet
5A03, formerly LF3, is a Chinese-standard aluminium-magnesium alloy with about 3.5 % magnesium and a deliberate silicon addition. It is stronger than 5A02, welds well and resists corrosion, and is used for welded structures, rail and transport panels and marine parts. Metline supplies 5A03 plate and sheet in O, H14, H24 and H112 to GB/T 3880, worldwide.
- Alloy
- 5A03 (LF3, Al-Mg 3.5)
- Tempers
- O, H14, H24, H34, H112
- Thickness
- 0.5 – 100 mm
- Standards
- GB/T 3880 · GB/T 3190
What is 5A03 aluminium?
5A03 contains 3.2 – 3.8 % magnesium, 0.30 – 0.6 % manganese and, unusually for a 5xxx alloy, 0.50 – 0.8 % silicon. It is non-heat-treatable and strengthened by cold work.
The higher magnesium gives clearly more strength than 5A02 while keeping good ductility and corrosion resistance. The silicon addition is intended to reduce hot cracking during welding, which is why 5A03 has long been used for welded structural parts, tanks and panels in Chinese-designed equipment.
There is no exact international equivalent. In magnesium content 5A03 sits between 5754 (2.6 – 3.6 %) and 5086 (3.5 – 4.5 %), but its silicon and manganese levels differ from both. Where a drawing permits substitution, 5754 or 5086 is usually reviewed as the alternative, depending on the strength needed.
5A03 chemical composition (wt %)
| Element | 5A03 (GB/T 3190) | 5754 (EN 573-3) for comparison |
|---|---|---|
| Silicon (Si) | 0.50 – 0.8 | ≤ 0.40 |
| Iron (Fe) | ≤ 0.50 | ≤ 0.40 |
| Copper (Cu) | ≤ 0.10 | ≤ 0.10 |
| Manganese (Mn) | 0.30 – 0.6 | ≤ 0.50 (Mn + Cr 0.10 – 0.60) |
| Magnesium (Mg) | 3.2 – 3.8 | 2.6 – 3.6 |
| Zinc (Zn) | ≤ 0.20 | ≤ 0.20 |
| Titanium (Ti) | ≤ 0.15 | ≤ 0.15 |
| Aluminium (Al) | Remainder | Remainder |
5A03 limits as listed in GB/T 3190; confirm against the edition named on your drawing.
5A03 mechanical properties
GB/T 3880.2 sets the binding minimums by temper and thickness. Indicative values for comparison are below; acceptance is against the standard and the mill certificate.
| Temper | Tensile strength (indicative) | Yield (indicative) | Elongation (indicative) |
|---|---|---|---|
| O | about 195 MPa minimum | about 100 MPa minimum | about 15 % minimum |
| H14 / H24 / H34 | about 225 MPa minimum | about 195 MPa minimum | about 8 % |
| H112 plate | about 175 – 185 MPa minimum, by thickness | about 70 – 80 MPa minimum | about 11 – 13 % |
Physical properties (typical)
- Density
- about 2.67 g/cm³
- Modulus of elasticity
- about 70 GPa
- Coefficient of thermal expansion
- about 24 µm/m·°C
5A03 sizes and weights
Supply range
- Thickness
- Sheet 0.5 – 6 mm (mainly O and H14/H24); plate 6 – 100 mm (mainly H112)
- Width
- 1000, 1200, 1250, 1500 mm; other widths on request
- Length
- 2000, 2500, 3000 mm or cut-to-size
- Surface
- Mill finish, PVC film one or both sides, paper interleaving
- Processing
- Shearing, saw cutting, laser and waterjet blanks
5A03 weighs about 2.67 kg per m² for each millimetre of thickness.
| Thickness (mm) | kg per m² | 1000 × 2000 mm (kg) | 1250 × 2500 mm (kg) | 1500 × 3000 mm (kg) |
|---|---|---|---|---|
| 1 | 2.67 | 5.3 | 8.3 | 12.0 |
| 1.5 | 4.00 | 8.0 | 12.5 | 18.0 |
| 2 | 5.34 | 10.7 | 16.7 | 24.0 |
| 3 | 8.01 | 16.0 | 25.0 | 36.0 |
| 4 | 10.68 | 21.4 | 33.4 | 48.1 |
| 5 | 13.35 | 26.7 | 41.7 | 60.1 |
| 6 | 16.02 | 32.0 | 50.1 | 72.1 |
| 8 | 21.36 | 42.7 | 66.8 | 96.1 |
| 10 | 26.70 | 53.4 | 83.4 | 120.1 |
| 12 | 32.04 | 64.1 | 100.1 | 144.2 |
| 16 | 42.72 | 85.4 | 133.5 | 192.2 |
| 20 | 53.40 | 106.8 | 166.9 | 240.3 |
| 25 | 66.75 | 133.5 | 208.6 | 300.4 |
| 30 | 80.10 | 160.2 | 250.3 | 360.4 |
| 40 | 106.80 | 213.6 | 333.8 | 480.6 |
| 50 | 133.50 | 267.0 | 417.2 | 600.8 |
Fabrication and applications
Forming
O and H24 form well; allow larger bend radii in H14/H34.
Service temperature
With magnesium above 3 %, avoid long-term service above about 65 °C, where Al-Mg alloys can become sensitised.
- Rail and transport: noise barrier panels, structural panels and vehicle bodies
- Marine: deck fittings, superstructure parts and welded panels
- Tanks and vessels: welded tanks and low-temperature equipment
- General engineering: welded frames and covers to GB drawings
Export packing uses interleaving paper or film, moisture-barrier wrap with desiccant, edge protection and ISPM 15 pallets or cases.
How to order 5A03
- SpecifyAlloy and temper (e.g. 5A03-H112), thickness, size, quantity, GB standard edition (or accepted equivalent) and surface needs.
- QuoteWe confirm alloy, temper, tolerances, certification, packing and delivery terms (EXW, FOB, CIF or DAP) for your destination.
- ProcessPlates are cut, filmed if required and inspected.
- DocumentEach delivery carries a mill test certificate to EN 10204 3.1 with the cast analysis and mechanical test results; third-party inspection can be arranged on request.
- ShipSheets and plates are interleaved or film-protected, packed in seaworthy wooden cases or on pallets, and shipped by sea or air on EXW, FOB, CIF or DAP terms.
References and standards
- GB/T 3190 – Chemical composition of wrought aluminium and aluminium alloys
- GB/T 3880.1 to .3 – Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets)
5A03 aluminium plate: frequently asked questions
What is the equivalent of 5A03?
There is no exact equivalent. Its magnesium (3.2 – 3.8 %) lies between 5754 and 5086, but its silicon (0.5 – 0.8 %) is higher than either. 5754 or 5086 is usually reviewed as an alternative.
Is 5A03 stronger than 5754?
In the annealed state it is broadly similar to slightly stronger, because of its higher magnesium. Compare the minimums in the specific standards for your temper and thickness.
Why does 5A03 contain silicon?
The silicon addition is intended to reduce hot cracking during welding of the alloy.
Can 5A03 be used above 65 °C?
Long-term service above about 65 °C is not recommended for Al-Mg alloys with more than 3 % magnesium because of sensitisation risk.
What does LF3 mean?
LF3 is the former Chinese designation for 5A03, meaning rust-proof aluminium number 3.
Need 5A03 plate or sheet?
Send the temper, thickness, sizes, quantity and standard. We will confirm availability, or an accepted equivalent, and a delivered price.
