AMS 2406
Plating, Chromium, Hard Deposit
Covers electrodeposited hard chromium plate.
What AMS 2406 specifies
AMS 2406 specifies hard chromium electrodeposit for wear surfaces and dimensional buildup. It does not provide a universal thickness class: the engineering drawing states plating thickness, final dimensions, and whether the deposit will be ground. The deposit must be at least 700 HV and substantially uniform on significant surfaces. Adhesion is a periodic test for non-ground plating, while plating that is subsequently ground must withstand grinding without separation. High-strength steel requires pre-plate stress relief and post-plate hydrogen-embrittlement relief under AMS 2759/9, with process testing where required. A complete note states pre-grind and final thickness, grinding allowance, critical surfaces, runouts, masking, and embrittlement treatment.
AMS 2406 types and classes
Every designation the document defines, with the thickness it requires and the tests it imposes.
| Designation | Meaning | Requirement / test |
|---|---|---|
Drawing-specified hard chromium | Hard chromium deposit with thickness and final dimensions controlled by the drawing. | Drawing-specified thickness; hardness at least 700 HV; adhesion or grinding integrity; hydrogen-embrittlement control. |
Tests and the drawing call-out
Tests the document imposes
- Thickness by ASTM B487, B499, B567, B568, B748, or approved method
- Hardness of at least 700 HV
- Adhesion per ASTM B571 for applicable non-ground deposits
- Ground deposit must withstand grinding without separation
- Hydrogen-embrittlement relief per AMS 2759/9
- Hydrogen-embrittlement process testing per ASTM F519 when required
How to cite it
Drawing call-out
HARD CHROME PLATE PER AMS 2406, <FINAL THICKNESS>, [PLATE THICKNESS BEFORE GRIND], [GRIND TO DIMENSION], [HYDROGEN-RELIEF REQUIREMENT], [MASKING]Angle brackets mark the choices the drawing must make; every finish page shows a completed example.
Finishes specified to AMS 2406
AMS 2406 — frequently asked
What thickness is AMS 2406 hard chrome?
The standard does not assign a universal thickness class. The drawing must state the deposit thickness and, when ground, both plating allowance and final dimension.
How hard is AMS 2406 chromium?
The deposit hardness requirement is at least 700 HV.
Does hard chrome require a hydrogen bake?
Susceptible high-strength steel requires hydrogen-embrittlement relief under AMS 2759/9. The drawing or order must identify basis-metal strength or hardness so the processor can apply the correct treatment.
AMS 2406 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 ↗