Aluminum Alloy Series Chart: 1xxx to 8xxx Explained
The four-digit number on an aluminium specification is not arbitrary. The first digit tells you the principal alloying element, and therefore most of what you need to know about how the metal behaves.
Learn the series and you can look at an unfamiliar grade and predict its character — whether it will weld, whether it will corrode, whether it can be heat treated, and roughly how strong it is.
The series system at a glance
| Series | Principal alloying element | Heat treatable | Corrosion resistance | Typical strength |
| 1xxx | None — ≥99% aluminium | No | Excellent | Low |
| 2xxx | Copper | Yes | Poor | Very high |
| 3xxx | Manganese | No | Good | Low–medium |
| 4xxx | Silicon | Some | Good | Medium |
| 5xxx | Magnesium | No | Excellent | Medium |
| 6xxx | Magnesium + silicon | Yes | Good | Medium–high |
| 7xxx | Zinc | Yes | Fair | Very high |
| 8xxx | Other (often Fe, Li, or foil-specific) | Varies | Varies | Varies |
1xxx — commercially pure aluminium
Composition: ≥99.00% aluminium, no deliberate major alloying addition.
| Grade | Purity | Character |
| 1050 | ≥99.50% | Excellent formability and conductivity; soft |
| 1060 | ≥99.60% | Slightly purer; excellent conductivity |
| 1070 | ≥99.70% | High purity |
| 1100 | ≥99.00% | Slightly stronger (minor Cu), excellent workability |
| 1145 | ≥99.45% | Foil grades |
| 1235 | ≥99.35% | Foil and flexible packaging |
Character: soft, extremely formable, excellent electrical and thermal conductivity, excellent corrosion resistance, not heat treatable, low strength.
Used for: foil and packaging, chemical equipment, electrical conductors and busbars, heat exchangers, deep-drawn cookware, reflective and decorative applications, battery current collector foil.
Choose 1xxx when you need conductivity, maximum formability, or corrosion resistance, and strength is not the priority.
2xxx — copper
Composition: copper as the principal addition (typically 3–6%).
| Grade | Note |
| 2024 | Classic aerospace alloy; high strength, good fatigue resistance |
| 2011 | Free-machining |
| 2014 / 2017 | High-strength forgings and structural |
Character: heat treatable, very high strength, good fatigue performance — but poor corrosion resistance and generally poor weldability. Usually clad or painted for protection.
Used for: aircraft structures, aerospace forgings, high-strength machined parts, military hardware.
Caveat: generally avoided in marine environments and in welded structures. Also anodizes poorly — not suitable for decorative anodizing.
3xxx — manganese
Composition: manganese as the principal addition (typically 1.0–1.5%).
| Grade | Note |
| 3003 | The general-purpose 3xxx alloy |
| 3004 | Higher strength; beverage can bodies |
| 3105 | Building products, roofing, siding |
Character: not heat treatable, moderate strength (roughly 20% stronger than 1xxx), excellent formability and weldability, good corrosion resistance.
Used for: cooking utensils, beverage cans, heat exchangers, roofing and siding, chemical equipment, general sheet metal work.
4xxx — silicon
Composition: silicon as the principal addition.
Character: lowers the melting point, improves fluidity. Primarily used as welding and brazing filler rather than as wrought product. Some 4xxx grades are heat treatable; 4xxx fillers are used with 6xxx base metal.
Used for: welding wire and brazing filler (4043, 4047), some pistons and wear-resistant applications.
5xxx — magnesium
Composition: magnesium as the principal addition (typically 0.5–5.5%).
| Grade | Magnesium | Note |
| 5005 | 0.5–1.1% | Architectural anodizing alloy |
| 5052 | 2.2–2.8% | The general marine and sheet metal alloy |
| 5083 | 4.0–4.9% | Structural marine; highest strength |
| 5086 | 3.5–4.5% | Marine and pressure vessels |
| 5754 | 2.6–3.6% | Automotive and general |
| 5182 | 4.0–5.0% | Beverage can ends |
Character: not heat treatable, medium-to-high strength from solid-solution strengthening, excellent corrosion resistance including marine, excellent weldability, good formability in softer tempers.
Used for: marine structures and boat building, vehicle bodies, pressure vessels, cryogenic applications, architectural panels, signage, cookware, can ends.
Choose 5xxx when you need corrosion resistance plus weldability. This is the marine and transport series.
6xxx — magnesium and silicon
Composition: magnesium and silicon, forming Mg₂Si, which makes the series heat treatable.
| Grade | Note |
| 6061 | The general-purpose structural alloy |
| 6063 | Architectural extrusions; excellent anodizing |
| 6082 | European structural equivalent; widely used in Europe |
| 6005 / 6005A | Structural extrusions |
Character: heat treatable (T6 is the common condition), medium-to-high strength, good corrosion resistance, good machinability, good weldability (though strength drops in the weld zone), excellent extrudability.
Used for: structural sections and extrusions, architectural frames and curtain wall, automotive components, bicycle frames, machined parts, piping, marine fittings.
Choose 6xxx when you need a heat-treatable, machinable, extrudable structural alloy with good all-round properties. 6061 is the most widely used aluminium alloy in general engineering.
7xxx — zinc
Composition: zinc as the principal addition, often with magnesium and copper.
| Grade | Note |
| 7075 | Highest-strength common aluminium alloy; aerospace |
| 7005 | Weldable, used in bicycle and motorcycle frames |
| 7050 / 7150 | Aerospace plate and forgings |
Character: heat treatable, the highest strengths available in wrought aluminium, but fair-to-poor corrosion resistance and generally poor weldability (with exceptions such as 7005).
Used for: aircraft structures, high-stress aerospace components, high-performance sporting goods, military applications.
Caveat: susceptible to stress corrosion cracking in some tempers; anodizes poorly; generally not chosen for marine service.
8xxx — other elements
A catch-all series for alloys not covered elsewhere. In foil, the 8xxx grades are among the most important in the world.
| Grade | Character | Use |
| 8011 | Al-Fe-Si | The workhorse packaging foil alloy — household foil, container foil, PTP pharmaceutical lidding, bottle caps |
| 8021 | Al-Fe-Si, very low Si | Cold-form pharmaceutical foil, high-barrier laminates |
| 8079 | Al-Fe-Si, low Si/Mn | High-barrier food and pharmaceutical foil, thin-gauge laminates |
| 8006 | Al-Fe-Mn | Container and packaging foil |
| 8090 / 8xxx Li grades | Aluminium-lithium | Aerospace, low density |
The key distinction inside 8xxx foil grades is purity of the minor elements. 8011 permits more silicon and manganese, making it stronger and cheaper. 8021 and 8079 restrict them, giving better ductility, fewer pinholes and better barrier — which is why they are used for cold forming and high-barrier applications.
Reading temper designations
The suffix after the grade describes the treatment condition:
| Suffix | Meaning |
| F | As fabricated |
| O | Annealed — softest, maximum formability |
| H | Strain hardened (with a second digit for degree, and sometimes a third for stabilisation) |
| H1x | Strain hardened only |
| H2x | Strain hardened and partially annealed |
| H3x | Strain hardened and stabilised |
| H12 / H14 / H16 / H18 | Quarter / half / three-quarter / full hard |
| H32 / H34 | Strain hardened and stabilised — the marine tempers |
| T | Thermally treated (heat treated) |
| T4 | Solution treated and naturally aged |
| T5 | Cooled from forming and artificially aged |
| T6 | Solution treated and artificially aged — peak strength |
| T651 | T6 plus stress relief by stretching |
Practical note: for non-heat-treatable alloys (1xxx, 3xxx, 5xxx) you will only see O and H tempers. For heat-treatable alloys (2xxx, 6xxx, 7xxx) you will see T tempers.
Quick selection guide
| If you need… | Series | Typical grade |
| Maximum formability or conductivity | 1xxx | 1050, 1060 |
| Packaging foil, general purpose | 8xxx | 8011 |
| High-barrier or cold-form foil | 8xxx | 8079, 8021 |
| General sheet metal, moderate strength | 3xxx | 3003 |
| Marine corrosion resistance | 5xxx | 5052 |
| Structural marine | 5xxx | 5083 |
| General structural, machinable | 6xxx | 6061 |
| Architectural extrusion, anodizing | 6xxx | 6063 |
| Maximum strength | 7xxx | 7075 |
| Aerospace structure | 2xxx / 7xxx | 2024, 7075 |
FAQ
What does the first digit of an aluminium grade mean? The principal alloying element: 1 = pure, 2 = copper, 3 = manganese, 4 = silicon, 5 = magnesium, 6 = magnesium + silicon, 7 = zinc, 8 = other.
Which aluminium series is strongest? 7xxx (zinc), led by 7075, gives the highest strengths in wrought aluminium. 2xxx (copper) is also very strong.
Which series has the best corrosion resistance? 1xxx and 5xxx. 5xxx (especially 5052, 5083, 5086) combines corrosion resistance with useful strength, which is why it dominates marine work.
Can all aluminium be heat treated? No. 2xxx, 6xxx and 7xxx are heat treatable. 1xxx, 3xxx and 4xxx are not — they gain strength only from work hardening (H tempers).
What is the difference between 6061 and 6063? 6061 is a general structural alloy with higher strength and better machinability. 6063 is an architectural extrusion alloy with better surface finish and superior anodizing response.
Why are 8011, 8021 and 8079 all used for foil? All are Al-Fe-Si alloys, but they differ in how tightly minor elements are restricted. 8011 permits more silicon and manganese — stronger, cheaper. 8021 and 8079 are purer — more ductile, fewer pinholes, better barrier.
What does T6 mean? Solution heat treated then artificially aged to peak strength. It applies only to heat-treatable alloys.
Which alloy should I choose for welding? 5xxx (5052, 5083) welds best and retains strength as-welded. 6xxx welds acceptably but loses strength in the heat-affected zone. 2xxx and 7xxx are generally poor.
Not sure which series you need?
Send us your application, environment, fabrication method and strength requirement. We will recommend a series and a grade — and tell you if a cheaper alloy will do the job.