If you’re in the manufacturing industry and are considering building a new production line or opening a new location, one of the things you’ll need to consider is your framing system. How will you mount your new equipment, and what structures will define the production flow? The traditional choice, of course, is welded steel, which is easily available and offers superior strength for heavy equipment. However, extruded aluminum framing systems have been gaining in popularity for several reasons.
Which is better for your facility? There are several factors to consider.
Extruded aluminum bars are made of an aluminum alloy (most commonly AA 6063) that has been forced through a die profile. Branded systems typically offer their own unique profile designs as well as t-nut or other fastening technology to securely connect bars together. There are several brands of extruded aluminum products, most of which offer an all-in-one system that also includes conveyor belts, pulleys and other elements needed for creating production lines.
Steel is the traditional choice for industrial framing systems, and has served its purpose well for many reasons:
1. Lower initial cost
The prices of metals are constantly fluctuating, but in general the price of carbon steel is about one-third of the price of aluminum alloy. The price you pay for materials may depend on additional factors, but in most cases steel is going to be one of the most affordable options.
2. Higher temperature resistance
If your manufacturing process will expose your framing system to extreme temperatures, you’ll want to consider the comparative melting points of the metals you use. Depending on the grade, steel melts at about 1,540° C (2,800° F). While pure aluminum has a low melting point, the process of alloying it raises its heat resistance significantly. Still, extruded aluminum alloys can melt at temperatures as low as 463° C (865° F), making it less reliable for extreme environments.
3. Superior strength
Combined with its relatively lower cost, the high strength of steel is what has made it the traditional choice for construction and framing. Carbon steel’s tensile strength measures at 635 megapascals (or 92,100 pounds per square inch), while aluminum alloy offers 190 MPa (or 28,000 psi) of tensile strength.
While extruded aluminum can’t compete with steel’s high strength and low cost, it does offer other advantages that may not be immediately apparent:
1. Lower installation cost
While steel itself is cheaper, there’s more that goes into building steel frames than just the materials. Welding is a time-intensive process, so the cost of installation time, equipment, and specialized labor must also be factored into the total. And if an active production floor will need to be shut down while welding is going on, the downtime must also be considered.
Most extruded aluminum framing systems, by contrast, can be assembled by a few employees using hand tools. No specialized equipment is required, and training time is at a minimum.
Also, since aluminum is so much lighter than steel, it’s possible to assemble parts of a structure off site and then transport them to the main production floor, avoiding the need to shut down the floor during construction.
2. Adaptability to change
Aluminum extrusion systems use t-slot fasteners, which can be secured along any part of the bar. No drilling or welding is required to connect elements, and connection points can be adjusted as needed. If you change out equipment, it’s very easy to move the fasteners or even rebuild an entire section of the frame without having to buy new aluminum bars.
3. Corrosion resistance
Aluminum is naturally rust-resistant, meaning aluminum extrusion frames are better suited for humid environments. They do not require applications of protective coating the way that steel does, and also do not need to be painted.
4. Comparable strength
While steel has a much higher tensile strength and higher melting point than aluminum alloy, an extruded aluminum frame system is sufficiently strong for many applications. And some extrusion systems are designed with extra strength in mind. The Robotunits extrusion system, for example, can provide near-identical strength for a 50 x 50 mm section of steel, and a single fastener can provide up to 8,800 pounds of strength. (See the photo demonstrating a single fastener supporting the weight of a car).
If your facility works under extreme temperatures or requires maximum strength, welded steel is probably still the best choice for you. However, if you are not in a high-temperature environment and can work with slightly lower strength, extruded aluminum provides an easier-to-install solution that can save you on labor efforts, plus better adapt to changes down the road.