How to Weld Steel to Aluminum
Welding steel-to-steel is incredibly common, but some toy with the idea of welding different metals together. While welding two different metals together can be possible, it’s important to keep in mind the compounds of both metals and how that will affect the strength of the bond. So, what about welding steel to aluminum? Are they able to create a durable bond? In this article, we’ll explain the science behind welding steel to aluminum, and what methods make it possible.
Can You Weld Steel to Aluminum?
No. You cannot directly weld steel to aluminum due to the intermetallic compounds produced during welding, which are prone to breaking. Even if you did try to weld steel to aluminum, the weld would be very weak and structurally unreliable. Welding aluminum-to-aluminum or steel-to-steel is much more common and practical.
This is using the traditional arc welding method, but there are alternative methods available, such as fastening, that make welding steel to aluminum possible.
Welding Steel to Aluminum: What you Need to Know
Steel and aluminum are very distinct metal types. When you look at their individual compounds and properties, it’s obvious to see that they’re very different from each other.
Steel is known for its weldability, strength, ductility, corrosion resistance, and toughness. On average, steel has a density of approximately 7000 kg/m³ to 8000 kg/m³, and a melting point of 2500°F. Certain steel types can be magnetic.
Aluminum is known for its corrosion resistance, thermal and electrical conductivity, and lightweightness, especially compared to other metal types. Due to its lightweight nature, it has an average density of 2,710kg/m3 with a melting point of 1220°F. Additionally, aluminum is non-magnetic.
The stark differences in magnetism, density, and melting points all affect the strength of a weld. For example, when two metals have very different melting points, there’s an inherent risk that the metal with a lower melting point will melt before metal with a higher melting point, leading to an uneven weld. Considering that steel has almost double the melting point of aluminum, it’s clear why welding steel to aluminum is notoriously difficult.
However, this doesn’t stop us from experimenting with using steel and aluminum together. What would a welding service provider like BSG do to bring a steel and aluminum welding project to life?
One of the most straightforward, affordable, and reliable methods of joining steel to aluminum is through fastening, rather than direct welding.
Connecting Steel to Aluminum with Fasteners
Fastening is a welding process which uses mechanical fasteners to join components, rather than weld two metals directly together.
Instead of permanently joining the metals, fasteners are often adjustable, which lends an appealing level of flexibility. Adjustable fasteners mean certain parts of the product can be disassembled, repaired, modified, or replaced with ease. Fastening is also a great alternative for projects using heat-sensitive components or materials.
There are also fastening methods that create permanent bonds when necessary. When we have a client looking to use steel and aluminum together, we use a one-step permanent fastening system certified by Canada and America’s national welding associations: the CWB and AWS.
This one-step welding process involves the use of weld studs which are end-joined to a metal workpiece instantly. It creates a permanent, high-quality bond while being more cost-effective than other fastening methods. Moreover, weld studs are applicable for areas which typically do not allow fastening.
Read More: Why Partnering with a Manufacturer Certified in CWB and AWS Welding Procedures Matters
Weld Carbon Steel to Aluminum with BSG
If your project requires the unique properties of both carbon steel and aluminum and the structural integrity of a permanent bond, BSG’s experienced stud welding team can help. With decades of experience in the manufacturing business, we’ve worked with a variety of industries and customers to bring their welding projects to life.
We’ll deliver your steel to aluminum welding project with impressive turnaround and quality. Our one-step fastening system creates a permanent bond between steel and aluminum in less than a second.
Get the bond you need without the time, cost, and unreliability associated with direct steel to aluminum welding.