What Are Coils?

Definition

Coils, also known as mattress springs, are the main source of support in innerspring mattresses. They are measured in gauges, with lower numbers meaning thicker coils. When purchasing a mattress, consumers should pay attention to both coil count and the construction of the coils, which will either be hourglass, pocketed, or continuous.

Types of Coils in Mattresses

Pocketed, or Marshall, coils are thin-gauge coils individually encased in fabric pockets, which reduces motion transfer in beds. Knotted, hourglass-shaped coils are laced together to form a simple innerspring unit. Finally, S-shaped coils, also known as continuous, provide a stable, interlinked system of support made from one long wire. Each of these coil types offers a unique feel. Some are even designed to treat issues like lower back pain.