Why is T6 the Most Popular Aluminum 6061 Grade?

As one of the most popular aluminum grades, 6061 is often chosen for structural applications, welded assemblies, electronics, and a variety of industrial and household items. 6061 aluminum tube, aluminum bar, and aluminum plate offer high-to-moderate strength, excellent corrosion resistance, and superior machinability and weldability. 6061 aluminum offers greater strength over other alloys in the 6xxx series, which is why it’s chosen for applications that require tough, yet light material.

6061 T6 is one of the most commonly requested versions of 6061 aluminum. The T6 refers to the temper or degree of hardness, which is achieved by precipitation hardening. This grade has a good strength-to-weight ratio and is also heat-treatable. With great formability and weldability, it is used for engineering and structural applications, boats, furniture, and more.

What is Tempering?

To understand what makes T6 special, it’s important to understand what tempering is and how it leads to each alloy’s tempers. Tempering is a treatment process applied to aluminum that has already been strengthened by heat treatment and that may have been hardened. It improves the workability and ductility of the material by relieving stresses that may have accumulated during the hardening process. Tempering helps create the desired characteristics, such as machinability and durability, that are required by the end application.

There are five main types of aluminum tempering designations:

1. T: Thermally treated. Applies to heat-treatable alloys that have been aged following a solution heat treatment.
2. H: Strain hardened. Suitable for non-heat-treatable alloys that have been strain hardened for strength.
3. O: Annealed. Annealing maximizes workability and toughness in the alloy’s lowest strength condition.
4. F: As fabricated. Most F-temper products are “semi-finished” products. They will be used in shaping, finishing, or thermal processes to achieve other finished forms or tempers.
5. W: Solution heat treated. This temper applies only to alloys that age naturally and spontaneously after solution heat treating.

What is a T6 Temper?

All T tempers are thermally treated. The number after the T indicates how the material was treated. The T type has 10 different variants, each designated by a number (1-10). The number designations (T1-T10) represent the manner in which the material was heat treated, cold worked, and aged to reach a stable condition.

The T6 temper designation means that the aluminum alloy has been given a solution heat treatment followed by quenching, cooling, and aging. Artificially aging allows the material to achieve the desired precipitation hardening.

What is 6061 T6 Aluminum?

Applying a T6 temper takes a piece of aluminum in the O (annealed) condition to a stronger, more durable condition. To create 6061 T6 aluminum, a 6061-O aluminum billet is heated to more than 900˚ F, water quenched, then aged for hours at a lower temperature. This is the foundation of the artificial aging distinction characteristic of T6.

How is the Yield Strength of 6061 Aluminum Improved by a T6 Temper?

By applying the T6 temper to 6061 aluminum, the typical yield strength nearly quadruples, from 8 ksi to about 35 ksi (ksi is a unit of stress).

What About Corrosion Resistance?

The 6xxx series of alloys, to which 6061-T6 belongs, is considered to have excellent corrosion resistance.

Is 6061 T6 Machinable?

Adding a T6 temper to 6061 aluminum in the O conditions improves its machinability from a D rating (poor) to a C rating (fair).

What are Some Common Applications for 6061 T6?

6061 T6 is a very popular material for good reason. It does well in applications that require strength and toughness – these characteristics allow it to shine in structural products and other products that require durability.

6061 T6 appears in watercraft frequently because it offers corrosion resistance, and it can be treated with a protective coating to improve its corrosion resistance even more. Boat components also benefit from 6061 T6 because it’s very strong and lightweight, yet durable. Its non-corrosive characteristics also lend themselves well to products like air and hydraulic piping and tubing.

Other common applications of 6061-T6 aluminum include bicycle frames, fly fishing reels, firearms, radio and remote-controlled items, and fire rescue ladders.

In What Product Lines is 6061 T6 Aluminum Available?

6061 T6 is available in aluminum tube, aluminum bar, and aluminum plate.

Why Pick 6061 T6 Aluminum For Your Project?

In short, 6061 T6 is a highly popular type of aluminum because of its versatility, strength, and forming characteristics. It’s ideal for projects that require a light, yet strong material.