Plating & metallizing · finish comparison
Cadmium Plating vs Zinc-Nickel Plating
Cadmium Plating and Zinc-Nickel Plating are both electroplating & electroless plating finishes; zinc-nickel resists corrosion better (720–1,000 h vs 200–500 h salt spray).
Cadmium Plating
Electroplating & electroless plating · $$$$
Cadmium is a sacrificial, lubricious coating retained mainly for aerospace, defense, and legacy hardware.
Zinc-Nickel Plating
Electroplating & electroless plating · $$ · instant quote
Zinc-nickel is a sacrificial alloy electrodeposit used on steel where plain zinc is insufficient.
When to choose which
Choose Cadmium plate
Cadmium plate is the pick when its strengths below matter more than Zinc-nickel's.
- Strong marine and aerospace sacrificial protection
- Useful lubricity and torque-tension behavior
- Typical 5–13 µm engineering thickness
Choose Zinc-nickel
Choose Zinc-nickel when a cadmium-free sacrificial replacement is qualified.
- Typically 720–1000 h to red rust for qualified 12–15% Ni systems
- Only 5–15 µm metallic deposit for precision steel parts
- Better heat and corrosion performance than plain zinc
What the numbers say
- Zinc-nickel resists corrosion better (720–1,000 h vs 200–500 h salt spray).
- Zinc-nickel is the harder surface (350–500 HV vs 40–60 HV).
- Zinc-nickel is the lower-cost option ($$).
- Cadmium plate tolerates more heat (230 °C continuous).
Scores side by side
Each score is 0–100 against every finish in this catalog. Corrosion is derived from salt-spray test duration and surface hardness from the finish layer's Vickers hardness where a measured figure exists; a finish that leaves the base metal's own surface is not rated for hardness. Cosmetic, lubricity and cost are FabDigit's engineering assessment. Scores and typical figures are screening data, not matched side-by-side tests or service-life rankings; ASTM B117 is a controlled salt-fog method, not a field-life prediction.
| Score | Cadmium plate | Zinc-nickel |
|---|---|---|
| Corrosion resistance | 70 Very good | 86 Excellent |
| Surface hardness / wear | 26 Low | 60 Good |
| Cosmetic quality | 38 Fair | 48 Fair |
| Lubricity | 68 Good | 28 Low |
| Cost | 75 $$$$ | 30 $$ |
Key numbers
| Property | Cadmium plate | Zinc-nickel |
|---|---|---|
| Thickness | 5–13 µm | 5–15 µm |
| Surface hardness | 40–60 HV | 350–500 HV |
| Salt-spray test duration | 200–500 h | 720–1,000 h |
| Max service temperature | 230 °C | 120 °C |
| Electrical | Conductive | Conductive |
| Colours | silver, yellow iridescent, olive drab | clear, black |
| Relative cost | High ($$$$) | Standard ($$) |
| Added lead time | 7–15 working days | 3–7 working days |
| RoHS | Restricted | Compliant |
| Instant quote | On request | Yes |
Bold marks the side that is ahead on a row where more (or less, for cost and lead time) is better. Ranges are the typical specification window; the drawing call-out fixes the class.
Which materials take each finish
| Material family | Cadmium plate | Zinc-nickel |
|---|---|---|
| Steel | Limited | Yes |
| DMLS / SLM | Limited | With care |
| Aluminum | Limited | Limited |
| Brass | Limited | Limited |
| Copper Alloy | Limited | Limited |
| Stainless Steel | Limited | Limited |
| Zinc Alloy | No | Limited |
Specifications and drawing call-outs
Cadmium plate
- AMS-QQ-P-416 — Plating, Cadmium (Electrodeposited)
- SAE AMS 2400 — Plating, Cadmium
CADMIUM PLATE PER AMS-QQ-P-416, TYPE II, CLASS 2, 0.0003 IN MIN; BAKE FOR HYDROGEN EMBRITTLEMENT RELIEF PER SPECIFICATION; AUTHORIZED AEROSPACE USE ONLY
Zinc-nickel
- ASTM B841 — Standard Specification for Electrodeposited Coatings of Zinc Nickel Alloy Deposits
ZINC-NICKEL PLATE PER ASTM B841, 12–15% Ni, 10 µm MIN, CLEAR TRIVALENT PASSIVATE AND SEALER; BAKE PER ASTM B850
Cadmium plate vs Zinc-nickel — frequently asked
What is the difference between Cadmium plate and Zinc-nickel?
Cadmium Plating and Zinc-Nickel Plating are both electroplating & electroless plating finishes; zinc-nickel resists corrosion better (720–1,000 h vs 200–500 h salt spray). Zinc-nickel is the harder surface (350–500 HV vs 40–60 HV). Zinc-nickel is the lower-cost option ($$).
When should I use Cadmium plate instead of Zinc-nickel?
Conversely: choose Zinc-nickel when a cadmium-free sacrificial replacement is qualified.
Is Cadmium plate or Zinc-nickel cheaper?
Zinc-nickel is the lower-cost finish ($$ against $$$$ for Cadmium plate) among the finishes FabDigit quotes. Both are priced per part with a lot minimum; the exact figure appears on the instant quote once the part is uploaded.
Which lasts longer in salt spray, Cadmium plate or Zinc-nickel?
Zinc-nickel. Cadmium plate is rated 200–500 h and Zinc-nickel 720–1,000 h in neutral salt spray (ASTM B117 or the qualification hours of the governing specification). The figures are for the finish as specified on a clean, properly pre-treated substrate; sealing, thickness class and substrate alloy move them.