Innerspring Mattresses:

Innerspring Mattresses– Innerspring mattresses are mattresses that are comprised of an inner core, coil or spring.  Almost all of us have slept on an innerspring mettress and they are the most popular type of mattress accounting for as much as 80% of the market.

Innerspring mattresses, developed in the 1860’s, brought a new level of comfort to sleepers, but were expensive for the time.  It wasn’t until after World War I that innerspring mattresses were mass-produced by Zalmon Simmons Jr.  Simmons debuted the Beautyrest mattress in 1926 for a cost of $39.50.  Though still expensive in comparison to other options, they proved to be so comfortable that millions of Americans began to purchase them.

The coils of the innerspring mattress provide the main support for the sleepers body.  Correct support is necessary for both a good nights sleep and a healthy spine.

Side view of Coil Innerspring Mattress support sytem

WHEN CHOOSING AN INNERSPRING MATTRESS, THERE ARE A NUMBER OF ASPECTS TO CONSIDER:

Coil Properties:

• Gauge– The thickness of the steel.  A lower number indicates thicker steel.  14-gauge steel is typical for most luxury mattresses.  The range generally found in mattresses is from 12.5 (very firm) to 16.5 (springier)
• Coil Count– Standard coil counts range from 250 to 1000.  It is not uncommon for a mattress with a lower coil count to have a lower gauge (thicker) steel.  Minimum coil counts for different innerspring mattresses would be 300 for a Full (Double) mattress, 375 for a Queen Size Mattress and 450 for a King size Mattress
• Working Turns– Measures how tightly the coil is wound.  Coils with a great number of working turns will result in both a softer and more durable mattress.  When determining ‘working turns’, each ½ turn or ‘spin’ of the coil equals a ‘turn’.
• Tempered– Tempered coils are those that have been heated and cooled to ensure retention of proper shape.  Double heat tempered coils have gone through the process twice, giving increased durability.

Coil Design:

• Hourglass (Bonnell & Offset)–
  • Bonnell has an hourglass shape, it is also known as the original innerspring mattress coil design and is the most prevalent in the industry.  It is found typically in less expensive innerspring mattresses.
  • Offset also has an hourglass design, but circles at the top and bottom are flattened to create a hinging action within the mattress core.  Allows the mattress to better conform to the sleepers body and tends to make the coils less noisy.  Offset coils tend to be found in more expensive mattresses.
• Pocketed Coils– (aka Marshall coils) Individually wrapped in a fabric pocket.  The pockets may be connected, but the coils are separate and can move independently.  Pocketed coils provide greater separation of movement, if your partner is tossing and turning, you are less likely to feel it.  You may have seen the Simmons Beautyrest commercials where the bowling ball is dropped on one half of the bed but doesn’t knock over a bowling pin on the other side of the bed.  That is a pocketed coil mattress.
• Continuous Coils– These springs are made from a single continuous length of wire shaped into a series of loose S-shaped ringlets.  Continuous coil design allows for more coils per mattress, which makes it difficult to compare with Hourglass and Pocket Coil mattress systems.

As with all mattresses, you should check out any mattress you are considering buying in person.  A quality innerspring mattress should last 7 to 10 years.