Aluminium alloys are grouped into series by their main alloying element, and each series behaves differently. Choosing the series first, then the alloy and temper, makes specifications clearer and quotations easier to compare.
The alloy series at a glance
- 1xxx — commercially pure aluminium (for example 1050). Excellent corrosion resistance, formability and conductivity, low strength. Used for cladding, reflectors, chemical equipment and general forming.
- 3xxx — manganese alloys (for example 3003, 3105). Moderate strength with good formability. Common in roofing, cookware, heat exchangers and building products.
- 5xxx — magnesium alloys (for example 5052, 5083). Good strength and excellent corrosion resistance, especially in seawater. Used in marine structures, tanks, trailers and pressure vessels. Strengthened by cold work, not by heat treatment.
- 6xxx — magnesium-silicon alloys (for example 6060, 6063, 6061, 6082). Heat-treatable and easy to extrude. The workhorse for profiles and structural sections.
- 7xxx — zinc alloys (for example 7075). Very high strength, used in aerospace and high-performance applications.
Choosing between 6063, 6061 and 6082
6063 (and 6060) extrudes easily into complex shapes with an excellent surface finish, which makes it the standard for windows, doors, curtain walls and anodised profiles. 6061 and 6082 offer higher strength for structural and engineering uses; 6082 is more common in Europe, 6061 in North America. For load-bearing designs, the alloy should be chosen by the designer, not substituted on price.
Tempers
- O — annealed, softest condition for maximum formability.
- H14, H24, H32 and similar — strain-hardened tempers for non-heat-treatable alloys (1xxx, 3xxx, 5xxx). The second digit indicates the degree of hardness.
- H111 — slightly strain-hardened, common for 5083 plate.
- T5 — cooled from extrusion and artificially aged; common for architectural 6063.
- T6 — solution heat-treated and artificially aged for maximum strength in 6xxx alloys.
Standards to quote
- Chemical composition: EN 573.
- Sheet, strip and plate: EN 485.
- Extruded bars, tubes and profiles: EN 755; precision profiles in 6060/6063: EN 12020.
- Primary ingot purity: commonly P1020A (99.7% aluminium).
Typical applications
- Architecture: 6063-T5/T6 profiles, 3xxx and 5xxx sheet for cladding and roofing.
- Marine: 5083-H111 plate and 6082-T6 sections.
- Transport: 5xxx sheet for trailers and tankers, 6xxx profiles for frames.
- Electrical and thermal: 1xxx conductors, 6063 heat sinks.
When requesting extrusions, include a drawing, the alloy and temper, finish (mill, anodised, powder-coated), length and annual volume, so die costs and minimum orders can be quoted accurately.