How to choose the right aluminium supplier / distributor
Anyone running an industry that needs the frequent use of aluminium to carry out architectural, structural or general fabrication applications will be looking to find the best aluminium suppliers. There is no way one can be sure that every supplier of aluminium offers the same range or quality of products. There are many things that one needs to look into when choosing the best supplier or distributor. The experience of the company, competitive pricing with value for money, and the timely delivery and wide product range are some of the things that one should check out before choosing the aluminium products supplier best suited to their needs.
The expertise of the aluminium supplier
One of the most important qualities that an aluminium products distributor should have is great knowledge aluminium. There are many companies that will store and ship this popular metal, but do not have any knowledge about the metal, its properties, its alloy, its uses and its limitations. An expert in aluminium metal will know about how soft the metal is, the importance of storing it dry and away from moisture, how it can get easily damaged when transported with heavier metals and so on. Hence, when one is choosing the metal supplier, it is important to choose one that knows aluminium in and out and also has a good reputation as an aluminium distributor in the market.
Value for money
Fair pricing is a factor you should consider when in the market for a reliable aluminium distributor. Reasonable rates are always a plus, especially if you’re looking to buy aluminium in large quantities. Many aluminium suppliers offer a comprehensive selection of products, but if their prices are too steep and they offer few discounts, it can be problematic buying the quantities you need. It’s essential to choose a company whose focus is on providing high quality products at competitive prices. This way, you’ll have the room on your budget to buy a suitable number of the products you require. A good supplier doesn’t just understand their business, they understand yours as well.
When purchasing aluminium there are many ways to take out cost;
- Buying material in the optimum sheet size can eliminate potential downstream machining processes in your operation.
- Choosing the correct alloy for your application.
- Buying protective coated sheet to prevent handling scratched during fabrication.
If you are not dealing with a supplier that is talking about these options, you should be.
Not all aluminium is the same
Aluminium is produced around the world by hundreds of mills, yet not all by the same processes. Ensure your aluminium distributor understands your fabrication processes and the end use. This can dictate the right aluminium product and the right method of production of the aluminium for your application and also avoid costly rework if the wrong type of aluminium is used.
Service and delivery performance
Good suppliers can be relied upon for prompt service. As a customer, you expect to receive your order within a reasonable time-frame, but more importantly, you expect to get it on the day it was promised. A professional supplier follows through with their commitment. The last thing you need is a supplier that doesn’t understand your business, or what it is costing you to have a piece of equipment sitting idle waiting for material to arrive that never did. Worthwhile distributors have the inventory, information tools, and customer service people to complete even the most complex orders quickly, efficiently and accurately. With the right supplier, you will feel confident that your parts will be ordered and filled to the correct specifications, packaged appropriately, and be delivered on time.
Melbourne / Somerton
109 Freight Drive
Somerton, VIC 3062
PO Box 1125 Epping, VIC 3076
Phone: 03 9409 8500
Fax: 03 9408 3946
23 Taminga Street,
Regency Park, SA 5010
PO Box 2103, Regency Park, SA 5942
Phone: 08 8300 1800
Fax: 08 8345 1044
The standard forms of mechanical fasteners – rivets, threaded fasteners, stitching and stapling – are available in aluminium and their use is always recommended for primary considerations when fastening aluminium parts. This recommendation stems from factors of compatibility, since dissimilar metals in contact can give rise to severe corrosion of one of the metals under certain conditions. Where the use of aluminium is plainly unsuitable, stainless steel is normally regarded as the best alternative.
A rapidly-evolving adhesives technology made possible by advances in polymer chemistry has made adhesive bonding a thoroughly practicable method of joining aluminium to itself and other materials and a wide range of synthetic resin formulations is exploited to join component parts operating in a variety of service conditions.
Soldering, brazing and welding differ primarily with respect to the temperature at which they are carried out. Temperatures used for soldering are appreciably lower than those for brazing; and in both soldering and brazing (unlike welding) the base metal does not heat to the point of fusion.
All common soldering processes can be used with aluminium, as well as some modern techniques better adapted to aluminium than to other metals.
5005 has good solderability, while 5052 has poor solderability and is not recommended due to its higher magnesium content causing intergranular penetration.
Brazing is a method of joining metal parts with a related alloy whose melting point is only slightly below that of the parent metal. In brazing aluminium , the filler metal is always an aluminium based alloy. The easiest aluminium alloys to braze are those in the 1000 and 3000 series and the low-magnesium alloys of the 5000 series, ie 5005. It is not recommended to braze 5052.
5005 and 5052 are readily weldable by standard techniques. It is frequently welded with GTAW (TIG) or GMAW (MIG). Aluminium must be very dry & clean to avoid contamination & porosity of the weld. Filler metals 1100, 4043 or 4047 are used. 4043 is the most crack tolerant. Best colour match is obtained with 1188 filler metal. Shielding gas must be dry and free of hydrogen.
Aluminium is one of the two common metals having an electrical conductivity high enough for use as an electrical conductor. The conductivity of electrical-conductor grade (alloy 1350) is approximately 36 mS/m (62% of IACS). Because aluminium has less than one-third the density of copper, an aluminium conductor of equivalent current carrying capacity is only half the mass of a copper conductor. With a significantly lower price per kilogram, aluminium is much more cost effective in many electrical applications.
The high thermal conductivity of aluminium came prominently into play in the first large-scale commercial application of the metal – in cooking utensils. This characteristic is important in heat exchange applications where the transfer of thermal energy from one medium to another is involved, either heating or cooling. Thus aluminium heat exchangers are common in the food, chemical, petroleum, aircraft and other industries.
Powder coating has become an important feature in the finishing of aluminium, both in the decoration and protection of aluminum. The aluminium requires to be cleaned thoroughly as for all applied coatings and an effective and efficient chromate conversion coating process must be carried out. The chromate conversion process is necessary for maximum adhesion and corrosion protection. Powder coated metal has to be stoved to cure the resins. Not only must the temperature be reached to achieve curing, but the temperature of the metal and coating must be high enough to complete the cross-linking of the resins and the particles must be fused to form a smooth and continuous layer.
Aluminium has a high resistance to corrosion because on surfaces exposed to the atmosphere, a thin transparent oxide skin forms immediately and protects the metal from further oxidation. Unless exposed to some substance or condition, which destroys this protective oxide coating, the metal remains protected against corrosion. Aluminium is highly resistant to weathering, even in industrial atmospheres, which often corrode other metals. It is also corrosion-resistant to attack by some acids. The metal can safely be used in the presence of certain mild alkalis with the aid of inhibitors, but general direct contact with alkaline substances should be avoided as these attack the oxide skin and are therefore corrosive to aluminium.
Some alloys are less resistant to corrosion than others, particularly certain high-strength alloys. Such alloys in some forms can be protected effectively from the majority of corrosive influences by cladding the exposed surface or surfaces with a thin layer of an appropriate aluminium alloy.
In accordance with sound design principles, direct contact with certain other metals should be avoided in the presence of an electrolyte as galvanic corrosion of the aluminium may take place in the vicinity of the contact area. Several well-established preventative measures can be applied.
The fact that aluminium is nontoxic was discovered in the early days of the industry. It is this characteristic which enables the metal to be used in cooking utensils without any harmful effects of the body, and today a great deal of aluminium equipment is used by food processing industries. The same characteristic permits aluminium foil wrapping to be used safely in direct contact with food products.
Under perfectly dry conditions aluminium buried in concrete needs no protection. In practice, however, such conditions are rarely achieved. It is therefore recommended that all aluminium surfaces in direct contact with concrete be coated with bituminous paint. The steel reinforcement used in concrete should never be allowed to come in contact with aluminium since galvanic corrosion will result. The chemical reactions may also cause spalling of the concrete.
When two dissimilar metals are coupled together in the presence of moisture a galvanic reaction may occur and cause corrosion of one of the metals. In such a circumstance the electrolytic couple formed produces a current flow from the less noble metal to the more noble metal and results in corrosion of the less noble metal. The phenomenon is usually consistent with the relative positions of the two metals in the electro-chemical series. Galvanic corrosion may be prevented by insulating dissimilar metals from each other with an electrically inert, non-absorbent barrier.
Aluminium will be attacked when subject to a galvanic reaction with mild steel, copper, brass, stainless steel and titanium.
Zinc will be attacked when subject to a galvanic reaction with aluminium.
Yes. It is frequently useful to coat the surface of aluminium parts with a film of another metal to achieve a specific appearance, increase resistance to wear, abrasion, or erosion, increase electrical conductivity, improve solderability, or improve frictional characteristics. Chromium plating of aluminium provides increased wear resistance, reduced friction and decorative functionality.
Steel components to be used in contact with aluminium may be galvanised. Zinc being generally anodic to aluminium, corrosion is to be expected at the zinc but not at the aluminium surface in contact with it. After a period, however, depending on the conditions and the mass of the zinc coating, failure may be expected, and if the aluminium is left in direct contact with the steel, bimetallic attack may follow at the expense of the aluminium.
The behaviour of couples composed of aluminium and stainless steels depends largely upon the passivity of the stainless steel. Thus it is generally safe to couple aluminium with 18/8 fully austenitic chromium-nickel stainless steel expect in the most unfavourable environments, such as continuous immersion in sea water. The ferritic and martensitic stainless steels, which are less strongly film forming, cause galvanic corrosion of aluminium in severe conditions.
Aluminium corrodes, see “Can aluminium corrode”,but it does not rust. Rust refers only to iron and steel corrosion. Aluminium is prone to corrosion. However, aluminium corrosion is aluminium oxide, a very hard material that actually protects the aluminium from further corrosion.
Is aluminium non-sparking and non-magnetic
Not so well known as some of the other properties of aluminium are its non-sparking (against itself and other non-ferrous metals) and non-magnetic characteristics. Nevertheless, these are of great importance for some uses. Its non-magnetic properties make the metal useful for electrical shielding purposes such as in busbar housings or enclosures for other electrical or magnetic equipment.
Is aluminium reflective
Aluminium is an excellent reflector of radiant energy through the entire range of wavelengths from ultra-violet through the visible spectrum to infrared and heat waves as well as electromagnetic waves of radio and radar.
Aluminium has a light reflectivity of over 80%, which has led to its wide use in lighting fixtures. These reflectivity characteristics lead to its use as an insulating material. For example, aluminium roofing reflects a high percentage of the sun’s heat so that buildings roofed with this material are cooler in summer. In the same way the excellent reflecting properties of aluminium ensure that buildings roofed with this material are warmer in winter.
Why aluminium is ductile
Ductility is the ability of a material to stretch without breaking under an applied stress, and is related to the toughness of a metal.
Aluminium is ductile because it has a face centred cubic (FCC) structure, which has lots of slip systems that atoms can use to move past each other rather than building up stress and forming a crack.
Which aluminium alloy is best
Aluminium comes in many different shapes and grades. The type of aluminium grade you choose ultimately depends on how you intend to use the metal. Your intended use allows you to rank the characteristics of each grade from most important to least important. This will help you narrow down the list of suitable grades. For example, if weldability is most important to your project, but strength is not, it may make sense to choose Alloy 1100, as this aluminium grade has excellent weldability, but is not typically used for high-strength or high-pressure applications.
Use this quick reference chart to quickly and easily find the aluminium grade that is right for you:
|Alloy 1100||Excellent||Excellent||Good||Excellent||Low||Metal Spinning|
|Alloy 3003||Excellent||Excellent||Good||Good||Medium||Chemical Equip|
|Alloy 5005||Good||Excellent||Poor||Excellent||Medium||General Sheet Metal|
|Alloy 5083||Poor||Good||Good||Good||High||Marine, Trucks|
|Alloy 6061||Good||Good||Good||Excellent||Medium||Structural App|
A unique combination of properties puts aluminium and its alloys among our most versatile engineering and construction materials. All alloys are light in weight, yet some have strengths greater than that of structural steel. The majority of alloys are highly durable under the majority of service conditions and no coloured salts are formed to stain adjacent surfaces or discolour products with which they come in contact, such as fabrics in the textile industry and solutions in chemical equipment. They have no toxic reaction. Aluminium and most of its alloys have good electrical and thermal conductivities and high reflectivity to both heat and light.
Aluminium and most of its alloys can easily be worked into any form and readily accept a wide variety of surface finishes.
Light weight is perhaps the best known characteristic of aluminium, with density of approximately 2.73 x 103 kilograms per cubic metre at 200C as compared with 8.89 x 103 for copper and 7.86 x 103 for carbon steel.
Types of Aluminium Alloys
Some aluminium alloys are heat treatable, some are not.
The non-heat treatable alloys contain small amounts of elements such as manganese, silicon, iron and magnesium in solid solution. The alloys can be strengthened by cold work or strain hardening, that is by rolling or drawing.
The heat treatable alloys contain elements such as copper, magnesium, zinc and silicon. The first step in heat treatment is to heat the alloy to a high temperature (~300 – 500oC, depending on the alloy) to take the alloying elements into solution. After cooling to room temperature, the metal is reheated to 100 – 200oC to allow second phase particles to form in the microstructure, which increases the strength (and reduces the ductility).
|Advantages of Aluminium|
|Advantages of Aluminium|
|Strong||Suitable for a wide range of finishes|
|High strength to weight ration||Virtually seamless|
|Resilient / tough||Easy to fabricate|
|Ductile at low temperatures||Joinable by various methods|
|Corrosion resistant||Suitable for complex, integral shapes|
|Non Toxic||Suitable for easy assembly designs|
|Heat conducting||Produced to precise, close tolerances|
|Reflective||Produced with uniform quality|
|Non magnetic||Cost effective|
|Non sparking||Provide freedom of design|
Aluminium Alloy Numbering and the Effect of Alloying Elements
The aluminium alloys were originally given 4 digit numbers assigned by the Aluminium Association USA, in a sequential order. Cast alloys were numbered in a similar way, with a 4 digit number including a decimal point. These numbers does not convey the content of the alloy, beyond the first digit, which sorts the alloys into groups, depending on the principal alloying elements.
Alloys are now often referred to by their UNS numbers. For wrought alloys, these add ‘A9’ before the Aluminium Association number, and for cast alloys ‘A0’ or ‘A1’.
|Wrought Alloys||Number||Cast Alloys||Number|
|Aluminium (Commercially pure, Al > 99.00%)||1xxx||Aluminium (Commercially pure, Al > 99.00%)||1xx.x|
|Manganese||3xxx||Silicon, + copper &/or magnesium||3xx.x|
|Magnesium & silicon||6xxx||Unused series||6xx.x|
|Unused series||9xxx||Other elements||9xx.x|
Temper Designation System
As fabricated. For wrought products, there are no mechanical property limits.
Annealed, recrystallised. Softest temper of the wrought products.
Strain hardened. Strength increased by cold work, which may be followed by a heat treatment for partial softening. The H is always followed by two or three digits indicating the treatment and result:
H1: Strain hardened only, no subsequent heat treatment.
H2: Strain hardened, then partially annealed to reduce their strength.
H3: Strain hardened, then heat treated to stabilize the strength – used for alloys containing magnesium only.
The second digit indicates the strength level achieved for the alloy:
0: Annealed 1: 1/8thHard 2: ¼ Hard 3: 3/8thHard
4: ½ Hard 5: 5/8thHard 6: ¾ Hard 7: 7/8thHard
8: Full Hard (~75% reduction of area in cold work) 9: Extra Hard
Some of the common aluminium alloys used in Australia
Grade Summary: This grade is commercially pure aluminum. It is soft and ductile with excellent workability. Ideal for applications involving intricate forming because it work-hardens more slowly than other alloys. It has the highest thermal conductivity of any aluminum alloy and its electrical conductivity is second only to the electrical conductor grade.
Typical Applications: Kitchenware, Giftware, Decorative trim, Intricate formed parts, Chemical and food processing industry parts.
Available products: Flat Sheet/Coil only
Typical Chemical Analysis: Cu – .05/.02 Si + Fe – .95 Max. Mn – .05 Max. Zn – .10 Max. Al-Remainder
Typical Density:2.71 kg/m3x 103
Typical Mechanical Properties
Tensile Strength 125MPa
Yield Point 115MPa
Grade Summary: It is essentially commercially pure aluminium with the addition of Manganese which increases strength some 20% over 1100. With excellent corrosion resistance and workability it can be deep drawn or spun, welded or brazed.
Typical Applications: Cooking utensils, kitchen equipment, decorative trim, awnings, siding, storage tanks, chemical equipment.
Available Products: Flat Sheet, Expanded Mesh Sheet, Perforated Sheet and Plate
Typical Chemical Analysis: Mn – 1.2 Cu – .20 Max. Si – .60 Max. Fe – .70 Zn – .10 Al-Remainder
Typical Density: 2.73 kg/m3x 103
Typical Mechanical Properties
Tensile Strength 150MPa
Yield Point 145MPa
Grade Summary: The most widely used of all aluminium alloys. It is essentially commercially pure aluminium with the addition of Magnesium which increases strength some 20% over 1100. With excellent corrosion resistance and workability it can be deep drawn or spun, welded or brazed.
Typical Applications: Cooking utensils, kitchen equipment, general sheet metal work.
Available products: Flat sheet, plate, coil and strip
Typical Chemical Analysis: Mg – 0.8 Al-Remainder
Typical Density:2.70 kg/m3x 103
Typical Mechanical Properties
Tensile Strength 160MPa
Yield Point 140MPa
Grade Summary: A higher strength alloy of the more common non-heat-treatable grades. Fatigue strength is higher than most aluminium alloys. Particularly good resistance to marine atmosphere and salt water corrosion. Excellent workability. It may be drawn or formed into intricate shapes and its slightly greater strength in the annealed condition minimizes tearing that can occur in 1100 or 3003. Excellent finishing characteristics with bright, clear anodic coatings.
Typical Applications: Wide variety from aircraft components to home appliances, marine and transportation industry parts, heavy duty cooking utensils, and equipment for bulk processing food.
Available Products: Flat Sheet and Plate
Typical Chemical Analysis:
- Cu – .10 Max. Si – .25 Max. Fe – .40 Max. Mn – .10 Max.
- Mg – .20/2.80 Max. Zn – .10 Cr – .15/.35 Al-Remainder
Typical Density: 2.69 kg/m3x 103
Typical Mechanical Properties
Tensile Strength 230MPa
Yield Point 195MPa
Grade Summary: This is the highest strength alloy of the more common non-heat-treatable grades. Particularly good resistance to marine atmosphere and salt water corrosion. Good workability and weldability.
Typical Applications: Unfired welded pressure vessels, marine, aircraft, truck, cryogenics, Should not be used above 65C.
Available Products: Heavy Gauge Flat Sheet and Plate
Typical Chemical Analysis:
- Mg – 4.5 Mn – 0.7 Cr – 0.15 Al-Remainder
Typical Density: 2.66 kg/m3x 103
Typical Mechanical Properties
Tensile Strength 315MPa
Yield Point 230MPa
Properties, fabrication & finishing
Commercially pure aluminium has a tensile strength of about 90 MPa. Its usefulness as a structural material in this form is thus somewhat limited. However, by working the metal, as by cold rolling, its strength can be approximately doubled. Much larger increases in strength can be obtained by alloying aluminium with small percentages of one or more other metals such as manganese, silicon, copper, magnesium or zinc. Like pure aluminium, the alloys are also made stronger by cold working. Some of the alloys are further strengthened and hardened by heat treatment so that today aluminium alloys having tensile strengths approaching 700 MPa have been developed.
A wide variety of mechanical characteristics, or tempers, are available in aluminium alloys through various combinations of cold working and heat treatment. In specifying the temper for any given product, the fabricating process and the amount of cold work to which it will subject the metal should be kept in mind. In other words, the temper specified should be such that the amount of cold work the metal will receive during fabrication will develop the desired characteristics in the finished product. At sub-zero temperatures aluminium alloys increase in strength without loss of ductility or brittle fracture problems, so that aluminium is a particularly useful metal for low-temperature applications including cryogenics.
Fabrication of Aluminium
Aluminium may be fabricated readily into any form. Often it can compete successfully with cheaper materials having a lower degree of workability. The metal can be cast by any method known to foundrymen; it can be rolled to any desired thickness down to foil approximately 0.006 mm: aluminium sheet can be stamped, drawn, spun or roll formed. The metal also may be hammered or forged. Aluminium wire, drawn from rod, may be stranded into cable of any desired size and type. There is almost no limit to the different shapes in which the metal may be extruded.
All aluminium alloys may be machined relatively speedily and easily, important factors contributing to the low cost of finished aluminium parts. The metal may be turned, milled, bored, or machined in other manners at the maximum speeds of which the majority of machines are capable. Another advantage of their flexible
machining characteristics is that aluminium rod and bar, particularly the free machining alloys such as 2011 and 6262, may readily be employed in the high-speed manufacture of automatic screw-machine parts.
Almost any method of joining is applicable to aluminium – riveting, welding, brazing, or soldering. A wide variety of mechanical aluminium fasteners simplifies the assembly of many products. Adhesive bonding of aluminium parts has been successfully employed in many applications including aircraft components and some building applications.
For many applications, aluminium needs no protective or decorative coating: the surface supplied is entirely adequate without further finishing. Mechanical finishes such as polishing, embossing, sand blasting, or wire brushing meet a variety of needs. Where the plain aluminium surface does not suffice, any of a wide variety of surface finishes may be applied. Chemical, electrochemical and paint finishes are all used. Many colors are available in both chemical and anodized finishes. If paint, lacquer, or enamel is used, any colour possible with these finishes may be applied. Porcelain enamels have been developed for aluminium and the metal may also be electroplated.