AMS 2473
Chemical Film Treatment for Aluminum Alloys, General Purpose Coating
Establishes requirements for general-purpose chemical-film conversion coatings on aluminum alloys.
What AMS 2473 specifies
AMS 2473 specifies a general-purpose chemical conversion film on aluminum, commonly used for corrosion protection and paint adhesion. It has no type, class, or thickness-grade table; the process is defined by the performance requirements of the controlled revision. The functional role is similar to MIL-DTL-5541 Class 1A, but the documents should not be substituted without customer approval. Process-control panels are evaluated for corrosion resistance, and painted specimens are evaluated for adhesion. The drawing should state AMS 2473, whether the surface remains unpainted or receives a specified primer or paint system, color if appearance is controlled, masking, contact areas, and allowed touch-up.
AMS 2473 types and classes
Every designation the document defines, with the thickness it requires and the tests it imposes.
| Designation | Meaning | Requirement / test |
|---|---|---|
General-purpose coating | Chemical conversion film for corrosion protection and paint adhesion on aluminum alloys. | Corrosion resistance, paint adhesion when applicable, and visual coating quality. |
Tests and the drawing call-out
Tests the document imposes
- ASTM B117 salt spray for 168 h on process-control specimens
- Wet-tape or specified paint-adhesion test
- Visual examination for continuous coating and objectionable powder
- Solution and process-control testing
How to cite it
Drawing call-out
CHEMICAL FILM TREAT PER AMS 2473, [COLOR], [PAINT SYSTEM], [MASKING], [TOUCH-UP LIMITS]Angle brackets mark the choices the drawing must make; every finish page shows a completed example.
AMS 2473 — frequently asked
Is AMS 2473 equivalent to MIL-DTL-5541 Class 1A?
They serve a similar general-purpose corrosion and paint-adhesion role, but they are separate specifications. Substitution requires review of the controlled requirements and customer approval.
Does AMS 2473 specify a thickness?
No dimensional thickness class is normally called out. The finish is controlled through process and performance testing.
When should AMS 2474 be used instead?
AMS 2474 is the legacy low-electrical-resistance chemical-film specification. Use it when electrical contact performance, rather than maximum general corrosion protection, controls.
AMS 2473 is copyrighted by SAE International. This page explains the document so a drawing can be read; it does not reproduce the standard. Purchase the current edition from the publisher. Official source ↗