What is the MIL-STD-889D Table IV galvanic series?

MIL-STD-889D Table IV is an ordered reference series of 61 metals, alloys, and surface treatments ranked by corrosion potential under static immersion in artificial seawater (ASTM D1141 without heavy metals), from most active (#1 Magnesium WE-43 Tagnite) to most noble (#61 Platinum).

Can Table IV rank order determine galvanic compatibility?

No. MIL-STD-889D Section 3.10 and the Table IV footnote explicitly state that Table IV is for reference only and must not be used to determine galvanic compatibility. Compatibility depends on coupled corrosion rates, anode-to-cathode surface area ratios, electrolyte conductivity, geometry, and service conditions.

How is compatibility determined under MIL-STD-889D?

Galvanic compatibility must be evaluated using MIL-STD-889D Tables I–III, which are based on experimentally measured coupled corrosion rates. Material pairs not included in Tables I–III require project-specific polarization data and review by the Cognizant Engineering Authority (CEA).

How does the pair identifier determine which metal is anodic?

In accordance with MIL-STD-889D Section 3.10, when two listed materials are in electrical contact in this electrolyte, the material positioned higher (more active) in Table IV is anodic and the material positioned lower (more noble) is cathodic.

Why are numeric open-circuit potential (OCP) values not listed?

MIL-STD-889D Table IV provides a verified relative rank order rather than discrete potential values. Because galvanic corrosion rates depend on dynamic polarization behavior rather than rank separation, numeric voltage differences are not used as compatibility thresholds.

Why do surface treatments like passivation and conversion coating affect rank?

Surface finishes alter surface oxide films and open-circuit potentials in seawater. For example, Table IV ranks passivated 304 stainless steel (#46) more noble than bare 304 stainless steel (#44), and chromate-treated aluminum alloys occupy different rank positions than untreated alloys.

Galvanic Series Reference

Look up the active-to-noble ranking of 61 materials from MIL-STD-889D Table IV in artificial seawater and identify the anodic and cathodic member of any pair.

MIL-STD-889D Mandatory Standard Limitation

Per MIL-STD-889D Section 3.10 and Table IV, this ordered series ranks materials solely by corrosion potential order under static immersion in artificial seawater (ASTM D1141 without heavy metals) and MUST NOT be used to determine galvanic compatibility. Potential difference or rank separation cannot predict compatibility or corrosion rates. Determining engineering compatibility requires the MIL-STD-889D Tables I–III coupled corrosion-rate matrix or application-specific polarization testing and review by the Cognizant Engineering Authority (CEA). In-service behavior is governed by coatings, passivation, cathode-to-anode surface area ratios, electrolyte chemistry, temperature, and geometry.

Galvanic Series Pair Reference

Select two materials from MIL-STD-889D Table IV to identify relative anodic and cathodic positions.

Material A

Material B

MIL-STD-889D Table IV Galvanic Series

Environment: Static immersion in artificial seawater (ASTM D1141 without heavy metals)

Rank

Material / Treatment State

Relative Activity

Source: MIL-STD-889D (7 July 2021), Table IV. Rank 1 is most active (anodic) and Rank 61 is most noble (cathodic) under static artificial seawater immersion. Table IV MUST NOT be used to evaluate galvanic compatibility. Compatibility determinations require the coupled corrosion-rate matrix in Tables I–III or application-specific testing and Cognizant Engineering Authority review.

Summary

Look up the active-to-noble ranking of 61 materials from MIL-STD-889D Table IV in artificial seawater and identify the anodic and cathodic member of any pair.

How it works

Browse the 61 materials ordered from most active (anodic) to most noble (cathodic) per MIL-STD-889D Table IV.
Data reflects static immersion in artificial seawater prepared according to ASTM D1141 without heavy metals.
Select two materials in the pair identifier to determine their relative positions in the series.
The tool identifies which selected material is anodic (higher/more active in Table IV) and which is cathodic (lower/more noble).
If the same material is selected twice, neither member is anodic relative to the other.
Rank order alone does not predict compatibility or corrosion rate; engineering compatibility requires MIL-STD-889D Tables I–III or testing reviewed by the Cognizant Engineering Authority (CEA).

Use cases

Identifying which material in a pair acts as the anode or cathode under MIL-STD-889D Table IV conditions.
Reviewing relative ranking of alloy variants and surface treatments (e.g., bare vs. conversion-coated aluminum, passivated stainless steels).
Serving as a baseline reference tool alongside MIL-STD-889D engineering assessments.
Confirming whether two materials occupy distinct rank positions in ASTM D1141 artificial seawater.
Instructional reference for materials engineering and corrosion science courses discussing the difference between series ranking and galvanic compatibility.

Frequently Asked Questions

Last updated: 2026-09-19 · Reviewed by Nham Vu