Plating

At a Glance

Applicable Materials

Types

Applications

Texture

Tin, Nickel, Electroless Nickel
Electrical connections, radiation shields, jewelry, low-friction environments
Leaves a glossy surface

About the Process

Plating is the process of adding a thin layer of metal onto the conductive surface of a part. Though primarily used to provide environmental and corrosive protection and for other functional effects, it also has decorative applications, such as for jewelry and architecture. There are many plating metals with various uses, such as gold, silver, chrome, rhodium, cadmium, though tin, nickel, and zinc are three of the most common in engineering applications.

In a similar process to anodizing, most plating (known as electroplating) starts with the base part being made anodic (given a positive charge) and submerged in a solution with the ionic plating metal. The plating metal is then supplied with electrons by a cathode, gets attracted to the anodic part, and a coating is formed. Coating thickness is controlled by varying voltages, currents, and duration of submersion.

Electroless nickel plating (ENP of NiP) is a slightly different process than the one described above. It uses a purely chemical reaction to induce plating and does not leverage electricity. Though this process takes much longer than electroplating, advantages are a more uniform thickness over even the most complex surfaces (due to not having to rely on varying electric fields) as well as superior wear and corrosion resistance. The standard specification for ENP in North America is MIL-C-26074E, with various grades specifying thicknesses from 0.0003-0.002”.

Design Recommendations

- This process adds thickness to a part’s surface, so plugging and masking threaded/reamed holes or other critical-to-function surfaces is recommended.
- Parts with intricate geometries may be difficult or impossible to uniformly plate.
- Our standard offering for ENP adds thickness between 0.0003”-0.0005”, although we can achieve 0.00005” up to 0.002" at special request.

Related Resources

Finishing Metal Parts Glossary