AMS-QQ-P-416
Plating, Cadmium (Electrodeposited)
Covers electrodeposited cadmium plating, supplementary chromate or phosphate treatments, thickness, corrosion resistance, and hydrogen-embrittlement control.
What AMS-QQ-P-416 specifies
AMS-QQ-P-416 is the SAE successor to cancelled Federal Specification QQ-P-416. Type I is cadmium as plated, Type II receives supplementary chromate treatment, and Type III receives supplementary phosphate treatment, normally as a paint base. Classes 1, 2, and 3 set minimum cadmium thickness at 0.0005, 0.0003, and 0.0002 in. Type II process-control specimens receive 96-hour salt spray. Susceptible steel requires pre-plate stress relief and post-plate hydrogen-embrittlement relief; the bake must begin within four hours, and supplementary Type II or III treatment follows the bake. The drawing should state type, class, basis-metal strength, supplementary color if controlled, embrittlement treatment, and masking.
AMS-QQ-P-416 types and classes
Every designation the document defines, with the thickness it requires and the tests it imposes.
| Designation | Meaning | Thickness | Requirement / test |
|---|---|---|---|
Type I Class 1 | Cadmium as plated, severe-service minimum thickness. | ≥ 13 µm ≥ 0.5 mil | Thickness, adhesion, quality, and hydrogen-embrittlement control as applicable. |
Type I Class 2 | Cadmium as plated, general-purpose minimum thickness. | ≥ 8 µm ≥ 0.3 mil | Thickness, adhesion, quality, and hydrogen-embrittlement control as applicable. |
Type I Class 3 | Cadmium as plated, thin minimum for dimensional constraint. | ≥ 5 µm ≥ 0.2 mil | Thickness, adhesion, quality, and hydrogen-embrittlement control as applicable. |
Type II Classes 1–3 | Cadmium with supplementary chromate; use the selected class minimum of 12.7, 7.62, or 5.08 µm. | ≥ 5 µm ≥ 0.2 mil | ASTM B117 salt spray for 96 h after at least 24 h aging; thickness, adhesion, and embrittlement control. |
Type III Classes 1–3 | Cadmium with supplementary phosphate, generally used as a paint base; use the selected class minimum of 12.7, 7.62, or 5.08 µm. | ≥ 5 µm ≥ 0.2 mil | Thickness, adhesion, supplementary-coating quality, paint-system requirements, and embrittlement control. |
Tests and the drawing call-out
Tests the document imposes
- Thickness by an approved ASTM method
- Adhesion per ASTM B571
- Type II ASTM B117 salt spray for 96 h
- Hydrogen-embrittlement relief bake started within 4 h for susceptible steel
- Hydrogen-embrittlement process testing per ASTM F519 when required
- Visual coverage and supplementary-treatment quality
How to cite it
Drawing call-out
CADMIUM PLATE PER AMS-QQ-P-416 TYPE <I|II|III>, CLASS <1|2|3>, [COLOR], [HYDROGEN-RELIEF REQUIREMENT], [MASKING]Angle brackets mark the choices the drawing must make; every finish page shows a completed example.
Finishes specified to AMS-QQ-P-416
AMS-QQ-P-416 — frequently asked
What is AMS-QQ-P-416 Type II Class 2?
It is electrodeposited cadmium at 0.0003 in, or 7.62 µm, minimum with a supplementary chromate treatment. It is the common general-purpose combination.
What do the classes mean?
Class 1 is 12.7 µm minimum, Class 2 is 7.62 µm, and Class 3 is 5.08 µm. The type separately identifies the supplementary treatment.
When is a hydrogen-relief bake required?
It depends on steel strength and hardness. Where required, the bake starts within four hours after plating and precedes the Type II or Type III supplementary treatment.
AMS-QQ-P-416 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 ↗