Blog
DIY Car Knowledge: Are Stainless Steel Fasteners Compatible with Aluminum?
Aluminum and stainless steel have very different properties, and each one is suitable for specific types of applications. However, you may find yourself facing a situation where the two meet. Before that happens, learn what you need to know about using stainless steel fasteners for aluminum.
Properties of Stainless Steel
Stainless steel is an alloy that contains 10% or more of chromium. The chromium creates a thin oxide layer over the metal improving its corrosion resistance. It is very durable, attractive, and easy to maintain, making it an appealing choice for many applications.
There are many different stainless variants, with stainless steel 316 among the most common. In addition to 16% to 18% chromium, it contains nickel (10% to 14%), molybdenum (2% to 3% ), and a small amount of carbon. Many stainless steel fasteners for aluminum are made from stainless steel 316.
The Problem With Mixing Aluminum and Stainless Steel
While stainless steel is a preferred material choice, many people hesitate to use it with aluminum components. There are many claims that it will lead to corrosion and failure of the aluminum. Like many rumors, there is a basis of truth to this claim.
Galvanic corrosion occurs when you pair dissimilar metals. It occurs when two metals come in contact under high moisture conditions and accelerate the self-corrosion rate of the weaker metal. In this case, aluminum will corrode more quickly than stainless steel.
The problem of pairing mixed metals is not limited to using stainless and aluminum; it extends to many dissimilar metals with differing properties. Luckily, there are things you can do to limit problems when using different metals on the same project.
Steps To Take When Pairing Dissimilar Metals
You may find yourself in a situation where you need to use stainless steel fasteners for aluminum components. You can reduce the risk of galvanic corrosion by creating a physical barrier between the stainless steel and aluminum. Using rubber bushing or washers to act as a barrier between fasteners and other components is a common example of this.
Since both metals are commonly used for automotive components and fasteners, it is only natural that products have evolved to address galvanic corrosion. One of the most effective is anti-seize grease. It acts as a physical barrier and greatly reduces corrosion common when mating dissimilar metals.
Stainless Fasteners on Aluminum Parts
So, are stainless steel fasteners compatible with aluminum? Despite many claims to the contrary, it is perfectly fine to use stainless steel fasteners on aluminum components. The key to this is to take proper precautions against corrosion. Using appropriate washers or bushings can help if the area may be exposed to moisture. If you will need to remove the fastener down the line, consider adding anti-seize to the threads.
High-Quality Stainless Steel Fasteners for Aluminum
When working on auto repairs, you want the best fastener for the job. In many cases, that will be made from stainless steel. Don't hesitate to use a great fastener just because it is a different material than the one you are securing. Shop ROGO Fastener for professional quality automotive fasteners, including stainless steel fasteners for aluminum components.
Sources:
- https://www.ampp.org/technical-research/impact/corrosion-basics/group-1/galvanic-corrosion
- https://www.aperam.com/stainless/what-is-stainless-steel/#