Aluminum is a complex metal that is versatile in its uses. Its light weight and ability to be extruded into a variety of shapes makes it one of the most used metals across a wealth of industries. Whether it’s panels on a spacecraft, the hood of an automobile or a window fame, aluminum is used in almost every aspect of our daily lives. So how is it machined? With its unique characteristics it can’t be machined in the same way you would brass, copper or stainless steel. Let’s first start with identifying what machining is.
Machining Defined
Machining is a manufacturing process that uses computer or manually operated tools to shape parts and products by removing unwanted pieces from a larger material. There’s a variety of methods to achieve the desired shape by using the machining process and some of the most common are:
- Welding
- Shearing
- Tumbling
- Grinding
- Deburring
- Boring
- Turning
- Water Jetting
- Plasma Cutting
- Tapping
- Drilling
- Sawing
Modern methods dictate that machining aluminum is done either using complex tools or, more commonly, crafted by CNC milling machines. CNC stands for Computer Numerical Control and allows for humans to input specifications into a computerized machine that will then go through the various processes to eliminate pieces of the material to perform one or multiple pieces that are formed to the tightest tolerances.
CNC milling, as this is often called, allows for consistent cutting of these parts in relatively short time frames. To create complex components, CNC milling uses the act of cutting along different axes to get the dimensions exactly right. This often completed using 3, 4 or 5 axis machining.
When it comes to producing thousands of parts and where accuracy is paramount, CNC turning is the preferred choice of machining. This accuracy is produced through the use of CAD/CAM software. Computer-Aided Design and Computer-Aided Manufacturing, known in the industry as CAD/CAM, allows an operator to design the product and control the manufacturing processes all from one place. Also available is CNC drilling. This method uses drill bits of various sizes to cut holes into various metals, including aluminum. Often, the drills rotate at over a thousand revolutions per minute. It is for aluminum’s unique characteristics that make machining and fabricating this metal much different than other metals.
Machining Aluminum Specifically
As one of the most popular choices of metals for a wide variety of industries, aluminum is the go-to material on many projects because of its unmatched light weight. Despite its light weight, it’s also extremely malleable and strong for the level of machinability it possesses. This is why it is among the most popular for the automotive, aerospace, construction, and technology industries.
As a comparison, let’s look at aluminum versus stainless steel. Aluminum is a third the weight of stainless steel. Though not as strong as stainless steel, aluminum is much easier to machine. When it comes to corrosion, aluminum is naturally much better suited to resist corrosion. This is because aluminum naturally forms what is known as an oxide layer. This layer spontaneously forms on the element and naturally protects it from further corrosion. However, stainless steel, with the addition of chromium, is also a strong fighter of corrosion. Aluminum is a better conductor of heat than stainless steel. Because it is more conductive, aluminum is a common element of AC units and car radiators. Workability goes to aluminum as well. Since it is considered a soft metal, aluminum is easily shaped and formed. Whereas, stainless steel is a much harder metal and difficult to shape. However, steel is a stronger metal. Therefore when it comes to welding, stainless steel is easier maneuver. Welding aluminum can often result in what is called burn through. Burn through occurs when aluminum begins to soften to the point of unworkability, which is around 400 degrees Fahrenheit. Finally, electrical conductivity is superior in aluminum over stainless steel. For this reason, aluminum is commonly used in wires and cables.
When fabricating aluminum the most important consideration when working the metal is speed. As easy as it is to form, it is difficult to weld. To avoid burn through, experienced welders know that aluminum is welded using high voltage and amperage setting to speed up weld-travel. Without this modification to the weld-travel, excessive burn through and destruction of the aluminum is a common outcome. One of the best alloys for aluminum welds is that of the 6xxx grade. This includes 6061 aluminum plateand extruded bar, which is commonly seen in architectural and agricultural applications, in pneumatic and hydraulic cylinder components and a wealth of other applications.
About Howard Precision
We’ve been in business for over 90 years. As one of the premier aluminum suppliers, who ONLY do aluminum, we offer premium aluminum products and use cutting-edge sawing technology to deliver the best the aluminum industry has to offer. Our in-house inventory is vast and comprised of top-notch products that have been milled from reliable sources. Because of our stringent quality standards, we don’t settle for any aluminum. We choose to purchase only the highest quality products from elite mills, which include a variety of aluminum plate, extruded rectangular, round, and square bars, cast tool and jig plate, custom aluminum extruded shapes and more. We are committed to providing our customers with the best aluminum products available.
For more information from one of our friendly customer service representatives or find out more about our stock list, contact us today.
