Upholstery Hardware

Upholstery Springs


Upholstery Springs

When you purchase springs  the spring measurements (4", 6", 8",etc) represent the approximate uncompressed height of the spring when you purchase it. Once you tie the springs they will be shorter. The chart below gives you a rough idea of what the height of the springs might be after they are tied. The actual height after they are tied will vary, as described below.

Height of Upholstery Seat Springs after they are tied (compressed)

This chart is intended to help you choose the approximate correct size of upholstery springs.

Here are the approximate sizes and compression ranges to upholstery coil springs for seats. Pick a spring size where the mid point is the nearest to your desired height. These seats springs are available in either 9 gauge medium or 8 gauge firm springs. The sizes are not meant to be an exact representation, but only an approximate height. There is a lot of room for variance in the height of each upholstery spring. If the height of the springs are a little too high for the space you can tie the springs down tighter, or you can reduce the amount of padding on top of the springs. If the springs are a little shorter than your desired height, don't tie them down quite as tight, or add more padding on top of the springs.

Lowest point represents the height after the springs at pulled tightly down to their approximate lowest point.

Mid Point represents the idea (mid range) height of the springs after their are tied. Use the midpoint to choose your desired spring height.

Highest point refers to highest (or loosest) point at which the springs might be tied. 

Upholstery Springs Compression Chart
Height Uncompressed Approximate Heights After Compression*
Spring Size Lowest point* Mid point* Highest point*
4" Tall Spring 3"    3 1/4"   3 1/2"
5" Tall Spring 3 1/4" 3 1/2" 4"
5 1/2" Tall Spring 3 1/2" 4" 4 1/2"
6" Tall Spring 4"    4 1/2"    4 3/4"
7" Tall Spring 4 1/2" 5" 5  3/4"
8" Tall Spring 5" 6" 6 1/2"
9" Tall Spring 6"   7"    7 1/2"
10" Tall Spring 7" 8" 8 1/2"
12" Tall Spring 9"    9 1/2"    10"

*Don't take the compressed height measurements too literally. Compression will vary depending upon spring wire gauge and the firmness of the springs. Use this chart only as a rough approximate guide.

Upholstery Springs are available in most of these sizes listed in the chart. However,  most suppliers only carry a few of the sizes. If your supplier doesn't carry the size you need, you may need to contact some other suppliers.

Controlling the firmness of the springs in the seat. 

There are several ways to control the firmness or softness of the seat springs.

First, you can order a firm, medium, or soft springs.

Secondly, you can control the firmness by how tight you compress the springs when you tie them. The more you compress the spring (such as to the lowest point on the chart), the firmer the springs will be.

Third, you can control the firmness or softness of the seat by how you space the springs. The closer the springs are to each other, the firmer the seat. The further away the springs are from each other, the softer the seat.

Gauge on springs

Generally the lower the number the firmer the spring (although there are exceptions, check with the supplier to be sure.)

  • The 8 gauge springs are the firmest grade,
  • 9 gauge come are the next firmest. However 9 gauge also comes in medium and firm, so check when one you are getting when you order them.
  • 13 guage springs are very soft that are used in the backrests of the furniture.

Types of Upholstery Coil Springs

Upholstery coil springs come in at least two types. One type has the wire loose at both ends. The other type has one end of the wire knotted. I prefer the type with the knotted end. When you place the springs in the furniture, always put the knotted end at the top.

Spacing of Springs

The circled ends of upholstery spring are approximately 4 1/2 in diameter.  In theory, the springs can be spaced anyway from about 5 1/2" to 8" or more (measured center to center.) The actual spacing will be determined by the measurement of the seat area and the desired firmness of the seat area. There is no hard fast rule as to exact spacing. However, here are some guidelines. The edges of the springs are generally about 1" inside the bottom of the arm frame


The firmness of the seat can be controlled in two ways. One, is to purchase either medium or firm springs, depending upon your what you choose. The other way to control the firmness of the spring is in the spacing. To build a firmer seat, space the springs very close together, with perhaps 1-2" inches between the springs. To build a softer seat, space the springs further apart, from 2-4" (or further) apart.

Before Purchasing the springs

If you are unfamiliar with the height of the springs I'd recommend that you first purchase 3 springs, one spring that is the height that you think you want, then buy one taller and one shorter spring. Then take them back to your shop and test each one to see which one seems best suited for the height that you want.

Testing The Spring Height

You test the spring by putting your hand flat on the top of the spring and pushing down. The spring pushes down fairly easily for the first inch or two (depending on the uncompressed height of the spring). Then, as you continue to press down you will find that the spring begins to push back up against your hand. It's at the point where you feel the spring press firmly up against your hand that will be the compressed height of the spring. Measure that height. This is not an exact science. This just give you an approximate finished height for your springs, and that measurement will vary a little, and that's OK.



Loop Springs

Vinyl Covered Loop Springs
  I had a client with a rocker that used these vinyl covered loops springs.

Vinyl Covered Loop Springs
  I had a client with a rocker that used these vinyl covered loops springs. 

    The client really wants to replace them with the same type as they are, but I told him that he might have to settle for rubber webbing. I had never seen them in any of my upholstery supply catalogs, so I went to the uphostery discussion forum at  www.carrscorner.com (of which I'm a member) and asked if anyone knew about these.





Shock 3 sizes







Jan, another member of www.carrscorner.com,  told me about using the shock cords/bungee cords (see below). So, as an experiment, I ordered and have now received shock cord. since I wasn't familiar with it and didn't know quite what to get, I ordered it in 3 different sizes; 3/16", 1/4", and 3/8".




Workable Solution for Loop Springs

Since the groove in the chair that the loop fits into is 1/4", I thought that it would be a simple choice, probably just use 1/4". However, once I had the cord in my hands, I found that the 1/4" cord stretches to over twice it's length, not a good thing for supporting the weight of an adult sitting on the seat cushions; the cord is much to stretchy. However, the 3/8" is very strong and seems like it will work very well.  However, it will only fit in the groove if stretched while it is put in the 1/4" groove. So it seems like this would work OK.



Cut  Cord to Size

It is better to cut the cord to size after you have fastened the ends together: Leaving about 8 inches to hang out, stretch and push the shock cord down into the groove back of the chair. Then, holdin that in place (with one hand, or with a clamp, stretch the cord tight across the open chair frame to the front of the chair. Stretch and push cord into the front groove. Pull the ends and overlap until the cord is tight (and, when you press down in the middle of the stretched cord, it only goes down a couple inches at most.

Now, hog rings the two ends together. Now take the cord out of the chair and  you should have a closed loop , like this:















Click on any picture to see a larger picture

After cutting to xize, and burning the ends to seal them, I used regular hog rings to fasten the ends together; they crimp the cord just right. (Can anyone suggest a better way to "finish-off" the joined area?)

  Thanks to  Jan from Carrscorner, for telling me about this.

Materials Used
    3/8" Shock Cord (1 yard per spring)
                057-0067  $.38 per ft*
    3/4" hog rings
                028-1217  $2.50 per 1# box*
Catalog numbers and prices are from B & H Upholstery, in Eugene Oregon.  Phone: 800-452-6078
You may be able to this shock cord / bungee cord at your local hardware store, or from your upholstery supplier

Editior's note: Since this type of spring is rarely used, because of time restraints, it was decided to leave this article unfinished for now. However, we will leave the web page here in case it can help someone.