Prices for nickel plating can vary quite a bit. So it is good to know what you are really paying for before you ask for a quote.
Part Size and Batch Volume
Larger parts are more expensive per piece than smaller parts as they require more chemicals and longer plating times. Smaller parts, however, become cheaper per unit as the setup time and handling time for a batch of smaller parts is shared amongst the pieces in the batch. So consolidating your orders can be cost effective.
Coating Thickness
Thicker coatings take longer to deposit and as a result are more expensive. A typical electroless nickel mid-phosphorus coating of 25 microns would be suitable for most general corrosion applications. However for greater protection a coating of 50 microns would be required and would cost roughly double that of a 25 micron coating. It is also important to note that if a customer requests a coating of 50 microns but does not specify this then the plater may well quote for a 25 micron coating as this is a more common size and would be a more cost effective option for the customer.
Phosphorus Content and Specification
Electroless Nickel Plating comes in 3 grades of Phosphorus – Low, Mid and High. The corrosion resistance of the coating, as well as the hardness, will vary depending on the grade of Phosphorus that is used. High Phosphorus coatings have the best corrosion resistance, whereas Low Phosphorus coatings are very hard but are not as flexible. Be sure to specify the correct grade of Phosphorus for your requirements to avoid any potential rework.
Part Geometry and Preparation
Parts with features such as deep bores, blind holes or intricate internal detail will take longer to process as the chemical solution will attempt to find an even surface to plate from. In addition to this, the surface finish of the part prior to plating will also increase the processing cost. Parts with heavily corroded or contaminated surfaces will require additional cleaning stages to achieve a satisfactory finish prior to nickel plating.
Post-Plate Heat Treatment and Compliance Costs
In addition to the cost of depositing the hardest corrosion resistant coating available, some applications require the coating to be as hard as possible, typically for wear resistance. This can be achieved by a post-plate heat treatment at around 400°C to produce a coating with a hardness of around 1000 HV. As nickel compounds are hazardous to health and subject to exposure limits at work, all professional nickel electroless plating companies have to add a handling overhead to all the costs quoted for all the processes in the nickel plating process.
There is more on Electroless Nickel Plating at www.swmf.co.uk/surface-coatings/electroless-nickel-plating/.
Understanding the various factors that affect the price of nickel plating allows you to set a realistic budget, and then compare quotes from various suppliers on an equal footing.
