Mechanical plating

Commonly plated workpieces include nails, screws, nuts, washers, stampings, springs, clips, and sintered iron components.

[2][3] The process involves tumbling the workpieces with a mixture of water, metal powder, media, and additives.

The surface conditioner lightly coats the workpiece in copper, while the medium removes any residual mill scale or oxides.

The medium that is already in the mixture cold welds the metal powder to the workpiece through impacts that are induced by the tumbling action of the tumbler.

The smaller media are omitted when the workpiece has a cavity that the medium can get caught in, such as a fastener's recessed head.

It can be as simple as a screen with water nozzles or as complicated as a vibratory system with magnetic separators.

[4] The greatest advantage of the process is its ability to overcome hydrogen embrittlement problems, which is important for workpieces that have a hardness greater than HRC 40.

[2] While this process does not cause problems with hydrogen embrittlement, and electroplating does, it still offers equivalent corrosion protection.

Moreover, because mechanical plating occurs at room temperature there is no tempering of hardened workpieces.