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Electro Deposition

Electroplating is a process that uses electric current to reduce dissolved metal cations so that they form a coherent metal coating on an electrode. Electroplating is primarily used to change the surface properties of an object (e.g. abrasion and wear resistance, corrosion protection, lubricity, aesthetic qualities, etc.), but may also be used to build up thickness on undersized parts.

The process used in electroplating is called electro deposition. The part to be plated is the cathode of the circuit. In one technique, the anode is made of the metal to be plated on the part. Both components are immersed in a solution called an electrolyte containing one or more dissolved metal salts as well as other ions that permit the flow of electricity. A power supply supplies a direct current to the anode, oxidizing the metal ions that it comprises and allowing them to dissolve in the solution. At the cathode, the dissolved metal ions in the electrolyte solution are reduced at the interface between the solution and the cathode, such that they ‘plate out’ onto the cathode. The rate at which the anode is dissolved is equal to the rate at which the cathode is plated, vis-a-vis the current through the circuit. In this manner, the ions in the electrolyte bath are continuously replenished by the anode.




Dull Nickel




Electro-plating on Aluminium

Hard Chrome


Salt Spray Testing

Stress Relieving/ De-Embrittling


In-house Laboratory


SPL is the region’s leader in Cadmium plating. Cadmium plating gives a silvery white metallic appearance with excellent corrosion resistance. The metal is also reasonably hard and very ductile therefore making it useful as a coating for work that requires flexibility.

We offer the following finishes for Cadmium:

Copper plating is the process in which a layer of copper is deposited on the item to be plated by using an electric current. At SPL, we offer a cyanide process. Copper is used as an undercoat or as a mask, prior to nitriding.

Copper plating is the process in which a layer of copper is deposited on the item to be plated by using an electric current. At SPL, we offer an alkaline process. With a higher current, hydrogen bubbles will form on the item to be plated, leaving surface imperfections. Often various other chemicals are added to improve plating uniformity and brightness. Without some form of additive, it is almost impossible to obtain a smooth plated surface. These additives can be anything from dish soap to proprietary compounds.


Hard chrome is used to reduce friction, improve durability through abrasion tolerance and wear resistance in general. We offer the following different Chrome


Hard chrome is very hard, measuring between 65 to 69HRC. Hard chrome tends to be thicker than decorative chrome, with standard thicknesses in non-salvage applications ranging from 0.2 to 0.6 mm (200 to 600 µm), but it can be an order of magnitude thicker for extreme wear resistance requirements, in such cases 1 mm (1,000 µm) or thicker provides optimal results. Unfortunately, such thicknesses emphasise the limitations of the process, which are overcome by plating extra thickness then grinding down and lapping to meet requirements or to improve the overall aesthetics of the chromed piece. 

Increasing plating thickness amplifies surface defects and roughness in proportional severity, because hard chrome does not have a levelling effect. Pieces that are not ideally shaped in reference to electric field geometries (nearly every piece sent in for plating, except spheres and egg-shaped objects) require even thicker plating to compensate for non-uniform deposition, and much of it is wasted when grinding the piece back to desired dimensions.

Hard chromium plating is subject to different types of quality requirements depending on the application; for instance, the plating on hydraulic piston rods is tested for corrosion resistance with a salt spray test.

We offer the following different Chrome processes:

  • Hard Chrome
  • Nickel/Flash Hard Chrome

Nickel electroplating is a process of depositing nickel on a metal part. Parts to be plated must be clean and free of dirt, corrosion, and defects before plating can begin. To clean and protect the part during the plating process, a combination of heat treating, cleaning, masking, pickling, and etching may be used.

We offer Dull Nickel as a nickel-plating process.

Silver has excellent lubrication and anti-galling properties. The even white matt coating produced is used extensively in high performance applications to prevent assemblies of similar materials from welding’ together thus allowing easy disassembly for servicing. Silver is particularly effective where threaded stainless steel components are assembled in high temperature applications.

We offer the following different silver processes:

The tin-plating process is used extensively to protect both ferrous and nonferrous surfaces. Tin is a useful metal for the food processing industry since it is non-toxic, ductile and corrosion resistant. The excellent ductility of tin allows a tin coated base metal sheet to be formed into a variety of shapes without damage to the surface tin layer. It provides sacrificial protection for copper, nickel, and other non-ferrous metals, but not for steel. Tin is also widely used in the electronics industry because of its ability to protect the base metal from oxidation thus preserving its solderability.

In electronic applications, 3% to 7% lead may be added to improve solderability and to prevent the growth of metallic “whiskers” in compression stressed deposits, which would otherwise cause electrical shorting. However, RoHS (Restriction of Hazardous Substances) regulations enacted in 2006 require that no lead be added intentionally, and that the maximum percentage must not exceed 1%. Some exemptions have been issued to RoHS requirements in critical electronics applications due to failures which are known to have occurred because of tin whisker formation.


Zinc coatings prevent oxidation of the protected metal by forming a barrier and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a Fine white dust that (in contrast to iron oxide) does not cause a breakdown of the substrate’s surface integrity as it is formed. Indeed, zinc oxide, if undisturbed, can act as a barrier to further oxidation, in a way similar to the protection afforded to aluminium and stainless steels by their oxide layers. The majority of hardware parts are zinc plated, rather than cadmium plated.

We offer the following different Zinc processes:


In-house masking design and manufacture capability