Your Guide to Common Aluminium Grades

Everywhere you look, you will find aluminium. In your kitchen appliances, your home, your car, bike and van, in the plane that flies you to somewhere sunny and in the canned beverage you drink whilst soaking in your surroundings. Sometimes the aluminium takes centre stage, like in the drink can or the frames of windows and doors and sometimes it is hidden in tiny electric components deep inside your technology.

Since aluminium is such a versatile material, it is no surprise to discover it isn’t always exactly formed with the same balance of raw materials. In fact, there are various aluminium grades in the UK, used to categorise the alloy involved, to ensure the optimum properties of the material are used for the appropriate purposes. This could be greater strength, better conductivity or higher heat resistance.

This is the International Alloy Designation System.

At LA Metals, we have a wide range of aluminium profiles in 6063 and 6082 aluminium grades, so, whatever your purpose, we have you covered. But what are the different grades of aluminium? Aluminium can be used for many purposes – let’s explore what each grade is made from and is capable of.

What are the Grades of Aluminium?

The International Alloy Designation System is designed to assist the construction of all aluminium applications by offering different aluminium grades to provide the most suitable material to ensure the best possible results. There are typically seven different aluminium grades, numbered from one to eight, to denote the alloys included and highlight their properties, and in this article, we are going to
explain each grade so you can be sure the material you use is ideal for its purpose.

Series 1xxx – 99%+ Pure Aluminium

Series one aluminium refers to a material that contains 99% pure aluminium or more. It has excellent corrosion resistance and electrical and thermal conductivity but is considered one of the weaker variants of common aluminium grades. This makes the material ideal for electrical applications or external use where it is exposed to the elements, but unsuitable where strength is key.

Series 2xxx – Copper Alloy

Series two aluminium alloys are primarily alloyed with copper. This combination results in increased strength but reduced corrosion resistance. To mitigate their shortcomings, series two grade aluminium profiles often require protective coatings should they be used in a corrosive environment. They are commonly used in aerospace, military vehicles and bridge building where a high strength-to-weight ratio is required.

Series 3xxx – Manganese Alloy

Series three aluminium is alloyed with manganese which makes it a go-between for series one and two. It has a moderate strength increase on series one without impacting the corrosion resistance as much as series two. This middle ground makes it one of the most popular choices from the aluminium grades chart and is often found in roofing, storage tanks, garage doors and kitchenware.

Series 4xxx – Silicon Alloy

Series four aluminium alloys are primarily formed with silicon, which lowers the melting point of the aluminium without producing brittleness, making it the ideal grade for welding and casting. It is commonly used for brazing filler materials and components requiring good resistance to thermal fatigue, like automotive pistons.

Series 5xxx – Magnesium Alloy

Series five aluminium alloys are primarily alloyed with magnesium. The addition of magnesium provides these alloys with increased strength compared to the one series and imparts excellent corrosion resistance. It is often used in marine environments for boat hulls, ship structures and other marine components. They are also often found in tankers, building facades and road vehicles that require corrosion resistance and moderate strength.

Series 6xxx – Magnesium and Silicon Alloy

Series six is primarily alloyed with magnesium and silicon. This results in an aluminium alloy that is both formable and workable, whilst possessing good strength and corrosion resistance. It is one of the most popular aluminium grades in the UK for fabricated products such as window frames, rails, automotive parts, furniture and more.

Series 7xxx – Zinc Alloy

Series seven denotes aluminium alloyed with zinc, which boosts the strength of the aluminium, making the series seven alloys one of the strongest materials. Many of these alloys also contain smaller amounts of manganese, copper and chromium to enhance their properties. Given its high strength, series seven is often found in aerospace applications such as aircraft wings and fuselages.

How to Check the Aluminium Grades?

It is imperative to check the grade of the aluminium to ensure you have the best material for your purpose as all grades are fabricated to highlight and heighten specific properties. To check the grade of your aluminium profile, when it is missing a label or documentation, you can attempt a spark test or, for more precise information, use an XRF chemical analyser or contact the manufacturer or retailer.

Why is it Important to Choose the Right Aluminium Grade?

It is always of the utmost importance to select the right material for the job. It’s also important to select an appropriate finish for the metal and to find out answers to questions like, what is anodising of aluminium? You wouldn’t use metal for microwavable plates, and you wouldn’t use paper for an oil tanker. It is the same with aluminium grades. At LA Metals, we pride ourselves on being the UK’s premier supplier of aluminium profiles and we didn’t earn this title by not studying our aluminium grades chart. We have been helping customers in multiple sectors to find the correct aluminium for their task for decades and fabricate bespoke pieces to fit any unique needs. Get in touch with our friendly team and let us ensure your project is a structural success.