Galvanic Series Chart: Active to Noble Metals
Top of chart = anodic (corrodes first). Bottom = more noble/cathodic. The ranking depends on the electrolyte and surface state.
| Order | Material / surface state |
|---|---|
| 2 | Magnesium EV-31 |
| 8 | Zinc |
| 14 | Al5083 |
| 16 | Al6061 |
| 21 | 1020 Steel |
| 25 | 1018 Steel |
| 30 | 4340 Steel |
| 32 | Tin |
| 36 | Ti-6Al-4V |
| 38 | Brass, Yellow |
| 42 | Copper |
| 44 | 304SS |
| 51 | 316SS |
| 53 | Monel® 400 |
| 59 | Silver |
| 61 | Platinum |
Selected entries in their MIL-STD-889D Table IV source order. Position is not a measured voltage or compatibility class.
A galvanic series shows relative direction. It cannot establish an exact corrosion rate or compatibility class by itself. Use the pair checker for that.
Common Galvanic Corrosion Compatibility Pairs
Quick answers from the source’s Table I (bare material) test matrix. Class 0 meets that standard’s compatible criterion; classes 1–6 do not. Results are not universal rankings for every environment.
| Metal pair | Class | Anodic material | Look up |
|---|---|---|---|
| Aluminum 6061 + stainless 316 | Class 5 | Al6061 | |
| Aluminum 6061 + copper | Class 4 | Al6061 | |
| 1020 steel + Inconel 600 | Class 3 | 1020 steel | |
| 304 stainless + 316 stainless | Class 0 | 304SS | |
| Zinc + 316 stainless | Class 5 | Zinc | |
| Magnesium AZ31-B + 316 stainless | Class 6 | Mg AZ31-B |
Class 0 = compatible under this test criterion. Classes 1–6 = incompatible under this criterion. A larger class indicates a larger tabulated anodic corrosion-rate band, not a universally calculated service risk.
Galvanic Corrosion Compatibility Checker
Choose the exact surface condition and two material designations. The result is read from the source matrix—no guessed anodic-index voltage threshold.
Without JavaScript: the galvanic-series chart, common-pair table, complete 61-material reference, and technical guidance remain visible. The exact pair checker requires JavaScript.
Table I compares source-listed bare material states.
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Choose two materials to look up their exact class.
Compare Alternate Metals for Your Selected Material
Once you select a material above, compare it against other listed options in the same source table. This is an exact class lookup, not a design-substitution recommendation.
Enable JavaScript to build the filtered material compatibility comparison; use the common-pair table and source-ordered series above without JavaScript.
| Other material | Class | Anode | Action |
|---|
Class 0 indicates compatibility only under the standard’s testing criterion. Confirm source conditions, electrical isolation and exposed area before adopting a material pair.
Galvanic Corrosion Classes 0–6 Explained
These are corrosion-rate bands for the anodic material in the standard’s specified static-immersion test, not severity labels for every real-world assembly.
| Class | Reported anodic corrosion-rate band | MIL-STD criterion |
|---|---|---|
| 0 | Below 0.009 mil/year | Compatible |
| 1 | 0.01–0.09 mil/year | Incompatible |
| 2 | 0.1–0.9 mil/year | Incompatible |
| 3 | 1–4.99 mil/year | Incompatible |
| 4 | 5–9.99 mil/year | Incompatible |
| 5 | 10–99.99 mil/year | Incompatible |
| 6 | Above 100 mil/year | Incompatible |
A class band must never be turned into one invented exact mil/year rate. If the material or treatment is missing from the official tables, this page reports no source result rather than guessing from a neighboring alloy.
How to Read a Galvanic Corrosion Chart Correctly
Identify the electrolyte
Wet exposure is necessary for a galvanic cell. Seawater, freshwater, humidity films, soil water, and process fluids are not interchangeable.
Match material and surface state
Use bare/bare, treated/treated, or bare/treated tables; do not treat passivated stainless, an aluminum alloy and a plated surface as interchangeable.
Identify the anodic member
For a coupled pair, the more active/anodic metal is the one subject to preferential galvanic attack. The order list locates polarity; source Tables I–III supply class.
Review area ratio and isolation
A small exposed anode coupled to a large cathode is an unfavorable geometry. Coatings, insulating washers, drainage and sealants can change exposure.
How to Reduce Galvanic Corrosion in Mixed-Metal Assemblies
Break electrical continuity
Consider insulating sleeves, nonconductive washers and other properly designed barriers where electrical bonding is not required.
Keep electrolytes out
Seal interfaces, enable drainage, avoid crevices, and use approved coatings and sealants suitable for the expected environment.
Check exposed area
Prefer small cathodic fasteners with a larger anodic sheet over the opposite area balance, where appropriate for the actual joint.
Verify materials and coatings
Specific alloy, passivation and conversion treatment matter. Check the installed finish and agency requirements, not just the bulk alloy family.
Galvanic Corrosion Chart Sources & Data Scope
Primary data: MIL-STD-889D, Galvanic Compatibility of Electrically Conductive Materials, Tables I–IV. The current source page provided this data and records Revision D, Notice 1 (29 April 2026).
This rebuild preserves all 1,830 pair classes as a compact machine-readable lookup and all 61 Table IV series entries; the former 5,000px-wide matrices are no longer forced into the document layout. The full row-by-row result for a selected material is available in the alternate-material browser above.
- DLA ASSIST — MIL-STD-889 record — authoritative document record and revision notices.
- MIL-STD-889D public-release PDF — the supplied page’s tabulation source for Tables I–IV.
- ASTM G82 — development and use of galvanic series for predicting corrosion performance; methodology context.
- ASTM D1141 — substitute ocean-water preparation, cited as the immersion-medium basis.
Galvanic Corrosion Chart FAQ
When electrically connected in a shared electrolyte, the relatively anodic metal can corrode preferentially. The exact alloy, surface condition, environment and exposed-area ratio control the practical outcome.
Not as a universal statement. As an example, Table I of MIL-STD-889D reports bare Al6061 coupled to bare 316SS as Class 5, incompatible under its specified immersed-artificial-seawater test criterion.
No. Differences in electrochemical kinetics, electrolyte, exposed-area ratio and surface condition can change the resulting corrosion rate. MIL-STD-889D compatibility classes are derived from an anodic corrosion-rate method rather than using a universal voltage-distance shortcut.
In a galvanic couple, the anode undergoes preferential oxidation/corrosion and the cathode participates in a reduction reaction. Which is which depends on the electrochemical environment and surface state.