The most common method of mounting toroidal transformers and inductors onto a chassis is to use a mounting kit comprising of a metal washer and two neoprene rubber washers. The single screw mounting saves labor and the two rubber washers provide cushioning and vibration proofing as well as additional electrical insulation.

Steel washers are provided with a central depression, which helps center the transformer and keeps the bolt head from protruding above the face of the washer. They are electro-zinc plated to provide some corrosion protection, but they are not intended for open outdoor applications.