Nickel Plating
Electrolytic nickel plating gives steel, copper and brass parts a hard, corrosion-resistant nickel layer, either bright for appearance or dull/semi-bright for engineering use. It is also the standard undercoat beneath decorative chrome.
What it is
Nickel is electroplated from a nickel sulphate (Watts type) or sulphamate bath. Bright nickel contains brighteners for a mirror-like finish; semi-bright and sulphamate nickel give a more ductile, lower-stress deposit for engineering purposes.
Because it is applied with an electric current, the thickness varies with part geometry: thicker on edges, thinner inside holes. Where a completely uniform coating is needed, electroless nickel (ENP) is the alternative.
Typical applications
- Decorative and corrosion-resistant finish on hardware and fittings
- Undercoat for decorative chrome plating
- Wear surfaces on moulds, rollers and tooling
- Salvage and build-up of worn or undersized parts (sulphamate nickel)
Suitable materials
- Carbon and alloy steel
- Copper, brass and bronze
- Zinc die castings (after copper strike)
- Stainless steel (with Wood's nickel strike)
Points to consider
- Specify bright or engineering nickel; the right choice depends on whether appearance or function matters most.
- Deep bores and blind holes receive little coating; consider ENP if they are critical.
- Nickel can cause skin allergies, so it is avoided on parts in prolonged skin contact.
- Surface defects in the base metal show through bright nickel, so polish first if a cosmetic finish is required.
Frequently asked questions
What is the difference between nickel plating and electroless nickel?
Electrolytic nickel uses an electric current and is thicker on edges than in recesses. Electroless nickel deposits chemically at an even thickness everywhere, including bores, and is harder.
Is nickel plating rust-proof?
It gives good corrosion resistance indoors and in mild conditions, provided the layer is thick enough and pore-free. For harsh outdoor use, a nickel-chrome system or zinc-nickel is usually better.
Can nickel plating be done on stainless steel?
Yes. Stainless steel needs a special nickel strike to break its natural oxide layer first, otherwise the plating will not adhere properly.