One of the biggest complaints we hear is that fasteners rust prematurely. The first question we might ask is “Are you within 20 miles of a saltwater environment?”
Surprisingly, a large number of customers say yes. It is commonly understood that metal rusts and that it rusts worse in corrosive environments. It is not commonly understood that these environments extend beyond what the eye can see, however this should be one of the most important factors taken into consideration when purchasing fasteners.
Stainless steel is a great example of this. Almost everyone you talk to can tell you that stainless steel is corrosion resistant, but did you know that grade 410 stainless steel is less resistant to corrosion because it is heat treated to be harder? or that grade 304 stainless steel is not suitable for highly corrosive environments?
With fasteners, material and sometimes even quality are important when it comes to choosing the right fastener for your installations. There are several materials that work very well in saltwater environments, some for this type of work and others that are almost certain to fail.
What should you use
There are generally some materials that work very well in saltwater environments. Depending on your needs, you should choose between the following:
- Grade 316 stainless steel
- Aluminum
- silicon bronze
These materials (or specific grades) are ideal for saltwater environments because they can resist the corrosive effects of saltwater very well.
Another option is HDG (hot dip galvanized) fasteners. HDG is a form of zinc coating that protects the fastener from damage and is generally a cheaper option, but it is not a perfect solution.
HDG fasteners may work well in certain saltwater environments, but results may vary depending on whether they are submerged, water temperature, and air temperature. Due to these factors, we do not recommend it as it will likely not perform as well as the materials listed above.
Pro tip
Although 316 stainless steel and aluminum are listed as good materials for use in corrosion-resistant environments, you also shouldn't mix the two. If you do this, the process of galvanic corrosion will more than likely occur, resulting in a reduced lifespan of your fasteners.
To see the fasteners we offer in these selections, check out our aluminum and marine grade fasteners pages.
