Galvanic corrosion happens when two different metals are joined in the presence of moisture, especially seawater. This free galvanic corrosion checker from HAGUE FASTENERS LIMITED shows which metal will corrode, how big the risk is in your environment, and how to reduce it, for fasteners in stainless steel, duplex, nickel alloys, titanium, copper alloys, carbon steel, zinc and aluminium.
Galvanic corrosion checker
Based on the galvanic series in flowing seawater (ASTM G82), using the middle of each published potential range. Guide limits for the potential difference follow common engineering practice for each environment. Real behaviour also depends on temperature, flow, coatings, crevices and the area ratio of the two metals.
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Guidance only. Results are approximate and for initial guidance. They are not a substitute for the governing standard, specification or drawing, or for testing. HAGUE FASTENERS LIMITED accepts no liability for decisions made using these tools. Always check critical values against the relevant standard. © 2026 HAGUE FASTENERS LIMITED.
How the galvanic corrosion checker works
Each metal has a typical electrical potential in seawater, from the galvanic series in ASTM G82. The bigger the difference between two metals, the stronger the driving force for corrosion, and the less noble metal (the anode) corrodes. The checker compares the difference with typical guide limits for the environment you choose, then allows for which part is the fastener: a small fastener that is less noble than the part around it corrodes fast, while a fastener more noble than the part is the safer way round.
Frequently asked questions
Can I use stainless steel bolts in aluminium?
Often yes in dry or normal outdoor conditions, because the bolt is small and more noble, so any attack on the aluminium is spread over a large area. In marine or wet conditions, isolate the bolt with insulating washers and sleeves and keep water out of the joint.
Can I use galvanised bolts in stainless steel?
Not in wet or marine conditions. The zinc coating and the steel bolt are both much less noble than stainless steel, and the small bolt will corrode quickly to protect the large stainless part. Use stainless steel or a more noble fastener instead.
What about offshore structures with cathodic protection?
Cathodic protection changes the picture, because it holds the whole joint at a protective potential. High strength fasteners under cathodic protection can also be at risk of hydrogen embrittlement. Follow your project materials and cathodic protection design, and ask us if you need help choosing fastener materials.
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