Return to Handy Data
 

 

Aluminium Association Four Digit Numbering System

• 1xxx series: Pure aluminium. Minimum aluminium content is 99% with no major alloying content.

• 2xxx-7xxx series: the major alloying elements are indicated by the first digit as follows:

• 2xxx: copper

• 3xxx: Manganese

• 4xxx: Magnesium

• 6xxx:Magnesium and Silicon

• 7xx: Zinc


Aluminium numbering system

As you might expect, each alloying element imparts a particular set of characteristics to aluminium, as follows:

• 1xxx series: pure, unalloyed aluminium is highly corrosive resistant, and has low strength. It is quite workable and is electronically conductive. It is non heat treatable.

• 2xxx series: when alloyed with copper the product has high strength, is hard, machineable, and can be heat-treated.

• 3xxx series: adding manganese produces a product with moderate strength, good workability, but is non-heat treatable.

• 5xxx series: magnesium-aluminium alloys are of moderate to high strength, good corrosion resistance. They are not heat treatable.

• 6xxx series: adding magnesium and silicone gives increased strength and corrosion resistance in a formable, heat treatable product.

• 7xxx series: zinc added to aluminium results in a good heat-treating qualities as well as the greatest strength of all commercial heat treated alloys.

In addition to the general qualities listed above, the 1xxx, 3xxx, 5xxx and 6xxx series all have good welding characteristics and corrosion resistance, while the remaining series (2xxx and 7xxx) have better mechanical properties but less desirable welding characteristics. In fact, while the there are a number of specific exceptions, the general rule is at increased strength in aluminium alloys is gained at the cost of reduced corrosion resistance and weldability.

In addition to the series number of an aluminium alloy, you will usually see a designation such as “T-3” or “T-6”, which refers to the temper of the alloy. The temper designation also describes the method by which the hardness was obtained. Temper designations differ between heat treatable and non heat-treatable alloys, as shown below:

F : designates a fabricated alloy

O : designates an annealed alloy

H : designates strain hardened
(the letter H is always followed by two or three digits, as in “H14”. The first digit indicates the tempering method.

• H1x means strain hardened only

• H2x means strain hardened then partially annealed

• H3x means strain hardened then stabilised.

The actual temper is indicated by the second digit, with added digits indicating variation from the standard practice.

• Hx2 (as in “H12”) means that the product is ¼ hard

• Hx4 means ½ hard

• Hx6 means full hard

• Hx9 means extra hard


Aluminium Selector Chart

Alloys

Available Forms

General Characteristics

Typical Uses
 

Sheet

Plate

Rod-Bar

Tube-Pipe

Extruded Shape

Structurals

Wire

Fasteners

    

1100

               

Excellent forming qualities. Resistance to corrosion. Weldability, electrical conductivity

Chemical equipment, heat exchanger, nameplates, coating utensils, decorative parts, and rivets.

2011

               

Good machinability. Unexcelled for free cutting quality. Good mechanical properties.

Screw machine products, hose parts, pipe sterns, tube fittings.

2017

                

Relatively high strength combined with fair workability and good machinability.

Same as above plus pulleys, coat hangers, knitting needles.

2024

               

High strength material of adequate workability. Has largely superseded 2017 for structural applications. Use of 2024-0 is not recommended unless subsequently heat-treated.

. aircraft parts, truck wheels, piano hinges, scientific instruments, ski poles.

Alclad 2024

               

Combines high strength 2024 with excellent resistance to corrosion in T3 and T4 temper. Its appearance is good.

Aircraft frames and skins, railroad car roofs, truck bodies, caul plates, and washers

3003

                

Similar characteristics to 1100 but with slightly higher strength, good workability, and low earring when deep down, weldability, resistance to corrosion. Low cost. ASIVE Unified Pressure Vessel Code Approved

Ductwork, cooking utensils, ice cube trays, pressure vessels, general sheet metal work.

5005

                

Similar characteristics to 3003, but with finer grain structure. Good finishing characteristics.

Same as 3003. Small boats,

5052

               

Excellent resistance to corrosion, especially marine environment. Good workability, higher strength than 1100 or 3003. Good finishing characteristics 5052-H112 Plate: ASME Unified Pressure Vessel Code Approved.

Kitchen cabinets, aircraft tube, bus and truck bodies, fan blades, trailers, shipping drums, and instrument cabinets.

5083

               

High strength, high resistance to corrosion, suitable for being welded.

Welded structures, pressure vessels, truck and marine applications, armour plates.

5086

                

Higher strength than 5052 with similar characteristics. Excellent resistance to corrosion in marine environment. Good workability and weldability.

Shipyard plate, tanks, structural and marine applications.

6061

               

Combines relatively high strength, good workability, and high resistance to corrosion, widely available. ASME Unified Pressure Vessel Code Approved.

Sailboats, canoes, mouldings, pipe, tanks, general structural and high pressure applications

6063

               

High resistance to corrosion. Pleasing natural finish greatly enhanced by the Alumite process.

Irrigation pipe, windows, stair rails, lighting standards
6262                

Good machinability with high strength. Corrosion resistance and finishing characteristics are better than 2011, 2017, 2024 and equal to 6061

Screw machine products, fittings, couplings, camera parts, nuts

Alclad 7075

               

Very high strength, excellent for resistance to corrosion in the T6 temper. Used for highly stressed structural parts. The O temper combines formability with high strength after heat-treating.

Aircraft skis, used where higher strengths than Alclad 2024 is required

7075

                

Very high strength material used for highly stressed structural parts. Used in applications where maximum corrosion resistance of Alclad 7075 is not required.

Keys, aerospace applications not requiring corrosion resistance of Alclad 7075.

 

DISCLAIMER:
The above information is provided for general information only. This data should not be used for design purposes. You should always consult your engineer for design guidance before selecting materials.