Protalloy® (Zinc-nickel electroplating)
Protalloy®, Zinc-nickel electroplating provides excellent corrosion resistance on cast iron and steel. Galvano Hengelo is highly specialised in zinc-nickel electroplating. At least 1,500 hours of corrosion protection can be achieved by applying an extremely thin coating of just 5 mμ.
Zinc-nickel electroplating is mainly used in hydraulic power transmission technology: manifolds, control valves and cylinders. Other sectors include machine and equipment construction, energy engineering and automotive industries.
Zinc nickel plating of hydraulic components
In the past, such components were often zinc-plated or chemically nickel-plated. However, there has been a clear shift towards zinc-nickel plating. With electrolytic zinc plating or chemical nickel plating, layer thicknesses of at least 30 μm are quickly required for some protection against red rust (for at least ±250 hours NSS). However, this layer thickness is often undesirable for the proper functioning of hydraulic components due to dimensional constraints.
A zinc-nickel layer has a thickness of only at least 5μm and provides protection of more than 1500 hours in the neutral salt spray test NSS. This makes this technique extremely suitable for critical components such as hydraulic cylinders. For example, are you experiencing internal corrosion in your cylinder heads? And is this leading to leaking seals? A zinc-nickel surface treatment can provide the solution. It is also possible to partially treat parts with zinc-nickel.

Electroplating zinc-nickel of machine components
Machine parts are often treated with zinc, chemical nickel or coated with wet paint. However, if the layer thickness plays an important role in dimensional accuracy, zinc-nickel, with a thickness of only 5 μm and more than 1500 hours of corrosion protection (NSS), is the solution. From a total cost perspective as well, zinc-nickel is often a better solution, as post-processing of fitting dimensions or masking of parts will not be necessary anymore.
Fewer corrosion products
Zinc-nickel forms a whitish film during a salt spray test: the white haze. Thereafter, the layer does not change for a very long time, up to many thousands of hours of NSS. This is also one of the important advantages over galvanic zinc coatings or other methods of galvanizing such as hot-dip galvanizing. This is because far fewer (voluminous) corrosion products are formed and the corrosion process is therefore considerably slower.
Protalloy®
Galvano Hengelo has optimized the galvanizing process so that it also offers maximum protection against a high moisture and salt load or against extreme temperature fluctuations. Under the name Protalloy®, the zinc-nickel alloy is passivated blank, possibly in combination with a thin topcoat. This passivation process is free of chromium-6. Protalloy® is therefore a high-quality protection without the disadvantageous properties of Cr6. This is in contrast to the old protection techniques in which a thick zinc layer with chromate passivation was applied.
Protalloy® is also a hard layer (up to 550 HV), which ensures better scratch and wear resistance than galvanic zinc and zinc iron. Protalloy is also a good basis (good adhesion) for applying a possible (optical) top layer such as lacquer or powder coating.

Specifications Protalloy®
You can find the specifications of the zinc-nickel with which we provide your product in the table.
Maximum product dimensions
LxBxH = 2100 x 300 x 1100 mm
Max. weight: 650 kg
Base material for Protalloy zinc-nickel electroplating: steel and cast Iron.
See our technical datasheet about Protalloy® under downloads for more info.
Properties of Protalloy® | ||
---|---|---|
Symbol | ZnNi | |
Content Zn | 84 - 90 | % |
Content Ni | 10 - 16 | % |
Corrosion resistance *) | > 1.500 | Hrs NSS |
Density (Zn) | ± 7,40 | g/cm3 |
Melting point (Zn) | ± 750 | °C |
Thermal stability | dood | |
Contact with aluminium | good |
*) hrs. NSS (Neutral Salt Spray test) acc. to ASTM B-117 until base metal corrosion Coating thickness > 5 micron zinc-nickel with transparent passivation and topcoat.
Protalloy® scratch test
Galvano Hengelo conducted a test to determine the extent to which Protalloy® is still protective after damage. In this test, a treated steel plate with 5-15 μm Protalloy® (zinc-nickel) was drimble-damaged by removing the zinc-nickel layer to slits 2 mm wide. The steel plate was then tested by placing it in the salt spray cabinet for 2,000 hours. The test has shown that the zinc-nickel layer bridges a distance of 2 mm wide steel for 2,000 hours. Only white rust occurs and no red rust. Watch the video of the entire test here.
Why Galvano Hengelo?
100% quality
We go for the highest quality possible
The specialist
We are specialized in electroplating
Fast delivery
We make every effort to guarantee the fastest possible delivery.
Zinc-nickel plating at Galvano Hengelo
Galvano Hengelo is highly specialized in zinc-nickel plating. We have the knowledge, the experience and resources. We have a modern X-Ray thickness gauge with which we can measure the thickness of the electroplated layers applied by us up to 0.01 μm (0.00001mm!) Also, we have a salt spray test chamber with which we can perform salt spray tests according to ASTM B117/ISO 9227. This allows us to accurately verify our own process and provide you with optimal service in comparing and testing the corrosion resistance of our layers versus existing systems.
- Expert in zinc-nickel plating due to years of experience
- Fast delivery times: 3 to 5 working days
- Large production capacity with the largest high-tech production line in the Netherlands
- Partial surface treatment possible
- Always the best solution for your product through an optimized process tailored to your product
- Option for passivation
Choose zinc-nickel plating with Galvano Hengelo!
*NSS = Neutral Salt Spray test, tested according to ASTM B117 (ISO9227)