For over 100 years mattresses have been using an innerspring or coil to provide support. Many different types of innerspring systems have been developed over the course of the past 100+ years. Which brings us to today’s topic: what are the main types of coil systems and what are the differences? Today there are 4 main coil types: Bonnell, Marshall, Offset, and Continuous.
The Bonnell coil has been used in bedding longer than any other coil. Originally developed for use in buggy seats, this coil can still be found in many low to mid range quality mattresses. These coils are hourglass shaped (think wider at the top and bottom, thinner in the middle) and provide decent support. The problem with Bonnell coils is that while they do provide decent support, they don’t last very long. Your typical Bonnell coil mattress comes with a maximum warranty of only 5 years. If you’re looking for a guest bedroom mattress or plan on replacing your mattress within 5 to 7 years, a Bonnell coil mattress is a good way to save money.
Next up is the Marshall Coil, also known as the individually wrapped or pocketed coil. A Marshal coil mattress contains rows of coils that are usually encased in fabric and then sewn together instead of being linked by steel wire. Marshal coils work independently meaning the coils you put pressure on are the only coils that push back. A Marshal coil is great at reducing the amount of motion that is felt when another person moves. If you’re a light sleeper or sleep with someone who is, a mattress that uses a marshal coil is a great choice. In addition to motion separation, a Marshal coil mattress is designed to provide a very gentle support compared to other “linked” coil systems. The two most popular brands that use a Marshal coil are Simmons Beautyrest and Stearns & Foster.
The third type of coil is the Offset coil. The Offset coil is another hourglass shaped coil, but unlike the Bonnell coil, portions of the top and bottom convolutions are flattened and then linked together by a series of helical wires. Offset coils are designed to conform better than other tied coil systems and provide excellent support as well as long term durability. Offset coils have made a big splash in the mattress industry thanks to the success of Sealy Posturepedic.
Last but not least is the Continuous coil. Continuous coils are very similar to an offset coil except the entire coil system is made from one piece of steel. Like the Offset coil, a Continuous coil system provides great support and long lasting durability (10+ years). The Continuous coil system can be found in the Serta Perfect Sleeper line of mattresses.
So you’re probably wondering, what coil system is the best? Well, it all depends on what you want out of your mattress. If you’re shopping for a mattress that is going to be used part time, or for a short amount of time-think college student- then a mattress that uses a Bonnell coil is going to save you money and get the job done. If you’re a light sleeper or sleep with someone who is, a Marshall coil mattress is the way to go due to it’s superior motion separation. If you’re looking for a solid support and want your mattress to last as long as possible, a mattress that uses an Offset or Continuous coil system is probably the best choice. After you have established what you want from your mattress remember this- whatever coil system you choose, if it’s for you and you want it to last, make sure you remember to choose a mattress that has at least a 10 year NON-PRORATED warranty.