If you work with metal on a regular basis you probably have some experience with fabrication. You also know that different types of metal can respond to fabrication methods in very unique ways, and that the processes suitable for aluminum fabrication won’t necessarily apply to other metals such as stainless steel. That’s why it’s imperative to familiarize yourself with the specific techniques associated with aluminum fabrication before you start experimenting.
Metal fabrication is what makes it possible for a wide variety of industries to use aluminum in their products. Whether it’s automobiles, solar panels, architectural structures or spacecraft, some amount of fabrication is necessary to get the aluminum parts to meet their requirements. Fortunately, aluminum has many properties that make it an ideal choice; over the past century many techniques have been developed to make it easier and more cost effective to work with.
What is fabrication?
Metal fabrication is the process of creating metal parts by means of cutting, bending and shaping the material. In industry, various means of fabrication are used to make parts and structures for machinery, products and even artwork. Typical forms of fabrication include welding, cutting, forming and machining. Some examples are tools, loose parts such as nuts and screws, structural frames, hand railings, pipes, automotive parts and more.
Today the fabrication processes for working with metals of all kinds can be done by both human labor and automation. Specialized shops, known as fab shops, are dedicated to fabricating. It’s important to note that in certain instances, machining is classified separately from fabricating, though there can often be quite a bit of overlap between the two processes. Indeed, most fab shops will also have machining capabilities as well.
The main types of fabrication include cutting, bending and assembling. Cutting is typically accomplished via sawing, shearing or chiseling the metal by hand or machine; or by using hand-held torches or an extremely powerful CNC cutter using a laser, mill bit, plasma jet or water jet. Hammers, press bakes or tube benders are employed when bending metal. Assembling describes the joining of two separate pieces of metal by welding, binding or riveting.
What properties make aluminum fabrication unique?
Because of aluminum’s unique properties, fabricating it can be very different from working with other metals. Aluminum’s light weight is common knowledge. This can be an advantage but at other times it can be a drawback. For instance, because it is not as strong as stainless steel, manufacturers often find that aluminum is easier to work with. Aluminum weighs approximately one third that of stainless steel. While having lower mechanical properties, it will often have a much higher strength to weight ratio.
As you likely already know, aluminum also has some specific issues when it comes to welding. It’s easy for an experienced welder to make the mistake of “burn through” because aluminum is characterized by greater thermal conductivity and a lower melting point than many other metals. Also, when feeding aluminum welding wire during the welding process, it can become easily tangled. This is due to the fact that aluminum wire is softer than steel and thus has decreased column strength.
One rule of thumb to remember when welding aluminum is to adequately clean the base material and make sure all aluminum oxide has been removed. The melting point of aluminum oxide is more than three times that of the base metal, meaning its presence will inhibit welding. Another concern is that the welder must be fast. Aluminum needs to be welded with high amperage and voltage settings, and faster weld-travel speeds. Welding too slow risks excessive burn through, especially when thin aluminum dimensions are being used.
Which alloys work best with which fabrication techniques?
The type of aluminum alloy used depends largely on the fabrication technique that is desired. Certain alloys are more easily welded than others. As a general rule the 1xxx, 3xxx, 4xxx, 5xxx, and 6xxx grades are best suited to welding applications. This includes the very popular and versatile 6061 variant found in all kinds of industries, from aerospace and automotive to packaging and communications. On the other hand, 2xxx and 7xxx alloys are not considered weldable, with just a few exceptions such as 2219 and 7003.
When it comes to bending, aluminum is often a prime material because of its formability. Many different alloys can be used, but some of the most common include 3003, 5052 and 6061. 3003 is especially good for bending, allowing for a generous bend radius and high elongation properties.
Your Trusted Technical Resources Partner
Aluminum alloys are highly desired when it comes to fabrication because of their superior formability, but it’s still critical that you pick the right material for your job. That’s why manufacturers and engineers need to work with partners who have the experience and commitment to quality necessary for a successful supply stream.
At Clinton Aluminum, we pride ourselves on our ability to support our customers through every step of the procurement process, from material selection to delivery. Whether you are looking to cut, weld, bend or bind aluminum, we’re standing ready to help.
Contact one of our friendly customer service representatives today to learn more about what aluminum alloy might be right for your fabrication job.