What is the galvanic series?

The galvanic series ranks metals and alloys by their electrochemical potential in a given electrolyte (typically seawater or a similar solution). A metal higher in the series (more noble) acts as a cathode; one lower (more active) acts as an anode and corrodes preferentially when the two are in electrical contact.

How much potential difference causes galvanic corrosion?

A difference of roughly 0.25 V or more is the common engineering threshold for a meaningful corrosion risk in humid or wet conditions. The actual severity depends on the surface area ratio, electrolyte conductivity, and exposure duration.

What is the standard hydrogen electrode (SHE)?

The SHE is the reference electrode assigned a potential of 0.000 V. All electrode potentials listed here are measured against this standard. A positive value means the metal is more noble than hydrogen; a negative value means it is more active.

Which metal corrodes when two dissimilar metals are in contact?

The more active (anodic) metal — the one with the more negative potential — corrodes. For example, when aluminum is in contact with copper in the presence of moisture, aluminum is the anode and will corrode.

Does this apply to dry environments?

Galvanic corrosion requires an electrolyte (such as water, salt solution, or humid air) to complete the circuit. In completely dry environments the reaction is negligible, but condensation and humidity are often sufficient to cause slow corrosion over time.

Galvanic Series Reference

Name: Galvanic Series Reference
Availability: InStock
Author: Nham Vu

Look up corrosion potential values for common metals and check galvanic compatibility between any two metals.

Compatibility Checker

Select two metals to check galvanic corrosion risk.

Metal A

Metal B

Galvanic Series — Standard Electrode Potentials

Metal / Alloy

E° (V vs SHE)

Activity

Potentials are approximate standard values (vs. SHE at 25 °C). Actual values vary with alloy composition, surface treatment, and electrolyte. Threshold for corrosion risk: |ΔE| ≥ 0.25 V.

Summary

Look up corrosion potential values for common metals and check galvanic compatibility between any two metals.

How it works

Browse the table to find a metal and see its standard electrode potential (V vs. SHE).
Metals higher on the table (more positive potential) are more noble (cathodic).
Metals lower on the table (more negative potential) are more active (anodic) and corrode first.
Select two metals in the compatibility checker to see the potential difference and corrosion risk.
A difference greater than 0.25 V is generally considered a corrosion risk in wet environments.
Use this reference when selecting materials for assemblies exposed to moisture or electrolytes.

Use cases

Engineering and design: avoid galvanic corrosion in fastener and fitting selection.
Marine and outdoor applications: choose compatible metals for saltwater environments.
Plumbing: verify pipe and fitting material compatibility.
Electronics: assess risk when mixing copper, aluminum, and steel components.
Educational reference for electrochemistry and corrosion science courses.
Welding and fabrication: confirm dissimilar metal weld compatibility.

Frequently Asked Questions

Last updated: 2026-06-18 · Reviewed by Nham Vu