Key Differences of 6061 Aluminum vs. 6063 Aluminum

The 6000 series of aluminum are aluminum alloys that are primarily alloyed with magnesium and silicon. As a class, they are sometimes thought of as ‘structural’ or ‘architectural’ aluminums. Two alloys in this class stand out due to how common they are: 6061 and 6063. These metals are found in just about every use of cut-to-size aluminum plate and bar stock making everything from bicycle frames to decorative windows. They combine their light weight with medium-to-high strength and excellent workability, making them very versatile.

In spite of being in the same class, and sharing many of the same properties, many still wonder about the differences in 6061 aluminum vs. 6063. They are differentiated in their use cases—some are merely aesthetic while others are more integral to their strength.

Mechanical Properties of 6061 Aluminum vs. 6063

Comparing 6061 vs. 6063 isn’t as straightforward as comparing one alloy to the other due to the two different tempers of each alloy in common use. The alloys are naturally aged T4 aluminum and artificially aged T6. Artificially aged (heat treated) 6061 and 6063 are both much stronger than T4 equivalents. A complete comparison of mechanical properties of 6061 aluminum vs. 6063 can be viewed in the table below:

As the table demonstrates, 6061 in its most common tempers is significantly stronger than its near equivalent 6063. Untempered naturally aged 6061 is roughly on par with heat treated 6063 aluminum and actually exceeds 6063 T6 aluminum’s shear strength. With aluminum 6061’s strength significantly outclassing 6063, some may wonder why anyone would choose anything but 6061 aluminum vs. 6063. The answer lies in the two alloys’ composition.

Aluminum alloy 6063 is a more purely aluminum alloy with fewer additional metals added. While this reduces its strength and can make it less workable than 6061, it does enhance the aluminum’s appearance, making it more amenable to aesthetic coating processes like anodizing.

Working With Aluminum 6061 vs. 6063

Aluminum 6061 is probably the most widely used aluminum alloy. It is certainly the aluminum alloy with the widest range of applications in industry. It is a good general purpose aluminum, and 6061 T6 comes with an extra margin of strength built in. Because of its strength, it’s used for everything from ambulance chassis to yacht hulls. In general, any fabricators or machinists that commonly work with aluminum will need a supply of 6061 around for general projects or to use around the shop. The same isn’t true of 6063 which sees its widest use in prefab architectural trim where strength is often secondary to appearances.

It is a common saying that when it comes to aluminum 6061 vs. 6063 aluminum that 6061 is a structural metal while 6063 is an architectural metal. Aluminum 6063 does have a great deal of strength. It can be used to make a great looking and impact resistant window frame that will keep a house intact through a hurricane. It isn’t a metal that can be used to build a bridge or other structure that can survive that same storm while 6061 aluminum is.

If you’re still wondering about 6061 vs. 6063, it’s important to know that Industrial Metal Service specializes in providing  process ready, cut to order aluminum 6061 to machine shops and fabricators nationwide. Contact us to secure 6061 aluminum cut-to-size at a fair price wherever you are in the continental United States.