BENDING ALUMINUM TUBING
Aluminum is often the material of choice by designers due to its high strength-to-weight ratio. It has great structural strength properties including toughness and hardness. It has good finishing characteristics; it is easily anodized in clear or many different colors. Aluminum offers good corrosion resistance and is easily welded. It also comes in many different shapes including flats, rounds, and structurals. But one thing that aluminum does not always offer is ease of workability, in particular forming/bending.
Aluminum bending machine (aluminum profile bending machine) can bend most all aluminum structural shapes. Structural shapes can be rolled in to rings for many uses, the corrosion resistance as well as its strength-to-weight ratio make aluminum rings very useful. Many sports and entertainment arenas use curved aluminum for its light weight and strength when making curved supports for overhead signage, display boards, and monitors.
Curving or rolling aluminum can be a little bit more difficult than curving or rolling normal carbon steel. If the operator is not familiar with the tendencies of aluminum, the material can crack or become deformed.
Further reading：Working with Curved Aluminum
Further reading：10 Things Everyone Should Know About Curved Steel
Aluminum is available in varying grades and tempers, and must undergo state-of-the-art processes to avoid cracking, work hardening, or collapsing at the bend.
Some types of aluminum are popular for decorative and ornamental use, while other alloyed grades deliver heavy-duty durability for industrial applications.
What tempers are best for bending aluminium?
This is an important question when buying material as the temper can greatly affect the outcome of the bending process. Using the correct temper for the job can reduce work time and costs over the course of a project.
We would suggest using the 6XXX series for bending as the grade has been very successful during bending trials over many years.
Harder or stiffer sections will often call for more tooling, time and effort to get the curves within dimensional tolerance.
Another aspect affected by the alloy and temper is the minimum radius. Some alloys are more forgiving during the bending process while some will be more prone to breaking or cracking. This means that stiffer sections are often limited with how tight each bend can be.
Benefits of Aluminum for Rolling & Bending
Aluminum is available in varying grades and tempers, and must undergo state-of-the-art processes to avoid cracking, work hardening, or collapsing at the bend. For your peace of mind, our team has specialized experience working with aluminum profiles in order to preserve their strength and appearance. After bending or rolling, each bent aluminum product goes through our stringent quality control process to assure its integrity.
Some types of aluminum are popular for decorative and ornamental use, while other alloyed grades deliver heavy-duty durability for industrial applications. Features and benefits of aluminum grades include:
Ductility & formability
Strength & fatigue resistance
Rust & corrosion resistance
Attractive design characteristics
Hygienic for food- and hospital-grade use
Sustainability & recyclability
Aluminum Bending & Rolling Applications
Applications of aluminum bending
- Condenser tubes & HVAC equipment
- Transportation equipment
- Food & pharmaceutical processing
- Aerospace & aircraft manufacturing
- Commercial lighting fixtures
- Signage & displays
Difference between 6061-t6 and 6063-t52
Although there are many different grades and tempers of aluminum, two of the most frequently worked with are 6061-T6 and 6063-T52.
6061-T6 has great formability, weldability and corrosion resistance. It has a tensile strength no more than 18,000 psi (125 MPa), and a maximum yield strength of no more than 8,000 psi (55MPa). One of the reasons that 6061-T6 is the most commonly worked with is that it can be elongated approximately 25-30% before it fails. While 6061-T6 has great qualities to work with, these qualities are most prevalent when the material is “fresh”. One of the unique qualities about aluminum is that it precipitation hardens, or in other words it age hardens. Precipitation hardening (age hardening) is a technique used to amplify yield strength of malleable materials. This process is also used on nickel, titanium and some stainless steels. Sometimes, aluminum has encountered too much hardening and must be heat-treated or stress relieved to adjust the formability. Included with this blog are photos of an example of how proper stress relief can take a tube that could not be rolled into one which rolls beautifully.
6063-T52 has generally good mechanical properties as well, and it is heat treated and easily welded. It has a tensile strength of at least 20,000 psi (152 MPa) and a yield strength of no more than 14,000 psi (110 MPa). Unlike the 25-30% elongation that 6061 presents, 6063-T52 can only be elongated 8%. The unique qualities of 6063 make its useful for architectural and ornamental applications.
6061-T6 and 6063-T6
Aluminum 6061-T6 and 6063-T6 are the most common grades and tempers of aluminum specified. The T6 represents the materials temper and its degree of hardness. Its high strength-to-weight ratio often makes it the best choice for structural applications, but it also makes the material extremely hard and brittle and therefore not the easiest of materials to work with when it comes to bending.
Often bender/rollers may encounter material failure in the form of cracking when pressures are applied, or after the material has been worked past a certain degree. When asked about the failure of 1 1/2″ Aluminum 6061-T6 & 6063-T6 pipe when being bent, The Aluminum Association replied with, “For greater bendability, 6061-T4 or 6063-T4 pipes of the same size should be considered… After bending, the pipes can be strengthened by artificial aging.” In the most basic of terms, if you experience material failure at a T6, try a lower temper. If a lower temper isn’t available then the only thing left to do is to explore the option of heat treating in order to reduce the material’s hardness.
Bending aluminum square tubing
How to bend aluminum without breaking it?
Bending aluminum square tubing can be a challenge.
There are several challenges involved in bending a big aluminum tube (6 x 6 x 1/4″) to a radius (95″ inside). First of all, the tube must be internally supported so that it does not crush. Then care must be taken not to have the inside wall go concave as it sometimes does. The right tooling must be used to avoid distortion including, for example, tooling that will match the sharp, square corners of the raw material.
And 6 x 6 x 1/4″ has a rather thin wall for a rather large tube. Lastly, rolling aluminum often scratches the surface of the material. A certain amount of scrubbing is necessary to maintain the cross-section of the tube while bending it to the desired radius. The challenge is how to keep the scratching to a minimum.
Depending on the application, all the above concerns may or may not apply. The curved aluminum tubes may be hidden from view and function just fine without great attention to minor imperfections. On the other hand, they may be exposed as an architectural feature that calls for great care.