Kaplama Karşılaştırması: Nikel vs Krom vs Çinko (2026 Seçim Kılavuzu)
Elektrokaplama mühendis kılavuzu: nikel vs krom vs çinko — korozyon, sertlik, görünüm, kalınlık ve maliyet; ayrıca akımsız nikel, sert krom, çinko-nikel ve karar yolu.
Elektrokaplama, bir parçanın yüzeyinin yapabileceklerini değiştirmek için ince bir metal katman biriktirir — korozyona direnç, aşınmaya direnç, daha iyi iletkenlik veya sadece doğru görünüm. En sık seçeceğiniz üçü nikel, krom ve çinkodur ve farklı sorunları çözerler: çinko pası ucuza önler, nikel korozyon ve aşınmayı iyi bir görünümle birleştirir, krom sertlik veya ayna parlaklığı katar. Parlaklığa değil, işe göre seçin.
Nickel vs chrome vs zinc at a glance
| Property | Nickel | Chrome | Zinc |
|---|---|---|---|
| Main job | Corrosion + wear + looks | Hardness or mirror finish | Sacrificial rust protection |
| Typical thickness | 5–50 µm | 0.1–1 µm (decorative), 5–500 µm (hard) | 5–25 µm |
| Corrosion resistance | Good | Good (over nickel) | Good but sacrificial |
| Hardness / wear | Good | Excellent (hard chrome) | Low |
| Appearance | Bright to satin | Bright mirror | Dull to bright, often passivated |
| Relative cost | Medium | Highest | Lowest |
What electroplating is
Electroplating uses an electric current to deposit a thin layer of one metal onto the surface of another. The part is the cathode in a plating bath; metal ions in the solution deposit onto it, building a controlled coating. Unlike anodizing (which converts the surface of aluminium) or PVD (a vacuum-deposited ceramic), plating adds a real metal layer — so it changes dimensions and can be built up thick.
Nickel plating — the balanced all-rounder
Nickel is the versatile middle ground: good corrosion resistance, good wear, and an attractive bright-to-satin finish. It’s often the base layer under decorative chrome, and it comes in two forms worth knowing.
- Electrolytic nickel: standard bath-plated nickel — bright or satin, general corrosion and appearance.
- Electroless nickel (EN): chemically deposited (no current), giving an extremely uniform thickness even on complex shapes and deep bores — and, when heat-treated, high hardness. The go-to for even coverage and wear.
- Best for: connectors, hardware, moulds, hydraulic parts, anything needing balanced corrosion + wear + looks.
- Watch-out: some people have a nickel skin sensitivity — relevant for consumer-contact parts.
Chrome plating — hard or mirror-bright
Chrome splits into two very different processes that share a name. Decide which you actually need — they’re not interchangeable.
Decorative chrome
- Very thin (0.1–1 µm), applied over a nickel layer.
- Bright, mirror-like, corrosion-protective finish.
- Automotive trim, fixtures, consumer goods.
Hard chrome
- Thick (5–500 µm), applied for function not looks.
- Very high hardness and wear resistance; can rebuild worn dimensions.
- Hydraulic rods, shafts, tooling, industrial wear parts.
Zinc plating — cheap sacrificial protection
Zinc plating is the workhorse of rust protection on steel — cheap, effective, and everywhere (think plated fasteners and brackets). Its trick is being sacrificial: zinc is more reactive than steel, so it corrodes first and protects the steel underneath even if the coating is scratched.
- Best for: steel fasteners, brackets, hardware — high-volume rust protection at low cost.
- Passivation / chromate: a post-plate chromate (clear, yellow, black) boosts corrosion life and sets the colour.
- Zinc-nickel alloy: a higher-performance variant with far better corrosion resistance for automotive under-hood and harsh environments.
- Watch-out: zinc has low hardness and poor performance in acidic environments — it’s protection, not wear resistance.
Gold, tin, silver & more
Beyond the big three, specialist platings solve specific problems:
- Gold: excellent conductivity and corrosion resistance — connector contacts, electronics.
- Tin: solderability and food-safe corrosion resistance — electrical terminals, food contact.
- Silver: highest electrical/thermal conductivity — high-current contacts, RF.
- Copper: often an underlayer for conductivity or to level the surface before nickel/chrome.
Substrate & dimensional effects
- Plating adds thickness — unlike a thin PVD film, plating (especially hard chrome or electroless nickel) can add enough to matter on a fit. Machine to compensate or mask critical surfaces, the same way you would for anodizing.
- Substrate matters: steel, brass and copper plate well; stainless often needs a strike layer; some substrates need an underplate for adhesion.
- Surface finish shows through on bright/decorative plating — polish before plating for a mirror result.
- Mask threads and press-fits that must stay exactly on size.
- Hydrogen embrittlement: high-strength steels can be embrittled by some plating processes and need a post-plate bake — flag high-strength parts to your finisher.
Because we machine and finish in-house, we work backward from the finished-part tolerance so the plating lands on-size. See our surface finishing service.
Which plating should you choose?
Not sure which fits your part and environment? Send the drawing and service conditions to our engineers via the surface finishing service and we’ll recommend the plating, thickness and masking.
Frequently asked questions
The questions engineers ask most about electroplating.
Sıkça Sorulan Sorular
- Zinc is the cheapest and protects steel from rust sacrificially (it corrodes first), but it’s soft. Nickel balances corrosion resistance, wear and an attractive finish, and is often the base under chrome. Chrome comes in two forms: thin decorative chrome for a bright mirror finish over nickel, and thick hard chrome for maximum hardness and wear. Choose by the job: zinc for rust protection, nickel for balance, chrome for hardness or shine.
- Electroless nickel (EN) is deposited chemically without an electric current, which gives it an extremely uniform thickness even on complex shapes, threads and deep bores where electrolytic plating would be uneven. Heat-treated EN also reaches high hardness. Use it when you need even coverage on complicated geometry or a hard, corrosion-resistant wear surface.
- Zinc is more chemically reactive than steel, so when a zinc-plated steel part is exposed to a corrosive environment, the zinc corrodes preferentially and protects the steel underneath — even if the coating gets scratched. That sacrificial behaviour is why zinc is so effective and popular for rust-proofing fasteners and hardware, despite being soft.
- Yes, but they need preparation. Stainless usually requires a nickel strike layer for adhesion; aluminium needs a zincate or similar pre-treatment before plating. Both are routinely plated for appearance, conductivity or wear. Note that aluminium is more often anodized than plated — see our anodizing guide to compare.
- Yes. Unlike a thin PVD film, plating adds a real metal layer — from a few microns for zinc or decorative chrome up to hundreds of microns for hard chrome. On tight fits, machine to compensate for the added thickness or mask the critical surfaces (threads, bearing bores, press-fits) so they stay exactly on size.
- For many wear applications, yes. Hard chrome uses hexavalent chromium, which has environmental and health concerns and is increasingly restricted. CrN PVD coating offers comparable hardness and wear resistance in a much thinner, cleaner layer, so it’s a common modern alternative — though hard chrome is still used where thick dimensional build-up is needed.
What’s the difference between nickel, chrome and zinc plating?
What is electroless nickel and when should I use it?
Why is zinc plating called "sacrificial"?
Can I plate stainless steel or aluminium?
Does plating change my part’s dimensions?
Is chrome plating being replaced by PVD?
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JLYPT Engineering Team
Surface Finishing & Plating Specialists
We machine parts and plate them, so we see how a finish choice plays out — corrosion life, appearance, fit and cost. This guide is how our finishing team picks between nickel, chrome and zinc plating for a real part instead of defaulting to whatever looks shiny.
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