The different types of bed spring and coil

The bed with a mattress composed of springs or coils is still the best seller in the UK and USA despite the increasing popularity of memory foam beds. Not surprisingly there are a number of good reasons for this.

The first is that there are a number of different spring or coil types and each has a varying level of quality, performance, assembly cost and retail price.

The second is that spring based beds have been around for a long time and they have a good track record, a unique springy feel and an association (which is not always appropriate) with quality.

What are the different bed spring types?

Depending upon the nature of the bed, and the bed terminology used in your part of the world, the three main types of bed spring may have different names. However, they are all essentially as described below. Some people like to call a bed spring a coil, but this is nothing more than a different name for the same thing.

• The Open Coil mattress is probably the oldest form of mattress and it is still popular today. Some think that the origin of this mattress dates back to the nineteenth century and the suspension systems that were once used on carts, wagons and other forms of horse drawn transport.

  The mattress is composed of springs or coils that are normally hourglass in profile and the coils are connected or laced together with wires called helicals to form a firm mesh of springs. This is one of two versions of what are described as innerspring mattress constructions and some people will refer to this form a spring and mattress as a Bonnell coil.

• The Continuous Coil mattress is really a modern development of the open coil mattress and the big difference is that every coil in the mattress is formed from a single strand of wire. The result is that every spring is connected directly or indirectly to every other spring.

  The main reason for the continuous coil’s format is ease of manufacture. The process of making all of the coils for one bed can be achieved in a single process using a single wire, it makes economic sense. Like the open coil mattress, the continuous coil mattress is an innerspring mattress. These coils are sometimes referred to as Mira coils.

• The Pocket Spring mattress sees a radical departure from the simple coil construction of the innerspring mattress and bed. Firstly the springs are barrel shaped and secondly they are manufactured individually and then set in a special fabric pocket. The result is that each spring compresses and flexes independently of all of the others that surround it.

  Beds made up of pocket springs can have very high spring counts (into the thousands) and the springs can be pre-compressed to change their character and tension. It is even possible to have the mattress divided up into different pressure zones with springs of a different gauge or tension occupying the different zones. Pocket springs are sometimes referred to as Marshall springs or coils and they are the springs found in high quality beds.

• Although open coil, continuous coil and pocket springs are the main coil or spring mattress constructions there is another variant and it is called the Offset Coil. The offset coil has a barrel shape like the pocket spring, however the bottom of the wires are flattened and allowed to hinge or rock by the use of helical wire.

So what do you get with springs - performance

Pocket springs are used for all the best non foam beds. The spring counts of these mattresses can be anything from 800 to 4000 or more. Pocket spring offer the best support of any coil or spring based system. Pocket springs may also be used in composite material beds where springs and a high performance foam are combined in a single mattress.

Both innerspring beds types have much lower spring counts and the mattresses that these beds produce are at the budget end of the bed market. Even so a innerspring mattress may well be comparable with a cheap low density memory foam mattress imported from Asia.