Types of Mattress Coils

An innerspring mattress, also called a coil mattress, contains spring coils to provide support for the persons lying on the bed. Coil mattresses come in support levels from soft to firm and in wide ranges of quality. Coils usually are made of steel, and come in four primary types. Nearly all mattresses sold are innerspring, as opposed to foam or airbed designs.

Most Common Type

Bonnell coils are the most prevalent and the least expensive type. This also is the lowest-quality mattress, providing the weakest support.

Bonnell Features

Bonnell coils are hourglass-shaped with five turns, and all coils are connected to each other.

Offset Features

Offset coils provide good support. This type also is hourglass in shape, but the system has a better design which prevents the mattress from sagging.

Continuous Coils

Continuous coils are similar to offset coils, only with a single steel wire strung through the mattress to produce small coils that provide better support.

Pocket Coils

Pocket coils create the highest quality mattresses, but they also tend to be the most expensive. These small coils are independent of each other to provide more comfort and support. Independent support also means less disturbance for sleeping partners when one person rolls over.