So you have torsion springs on a steel rolling door. To learn more about how your torsion spring system works, jump down to our Introduction to Steel Rolling Door Torsion Springs. The rest of this page is dedicated to helping you determine what torsion spring you need for your roll-up door.
The torsion springs on steel rolling doors work the same way as other torsion springs in the garage door industry. When the door is closed, the spring is wound. The spring is secured to a spring anchor bracket on one end and to the shaft on the other. When the steel rolling door opens, the spring in the barrel supports most of the door weight. The remainder of this weight is lifted by the chain hoist or the operator.
As the steel rolling door opens, the slats wrap around the barrel. Meanwhile, the torsion spring unwinds. When the door is fully open, there is still a small amount of tension in the spring to keep the door from unrolling.
While the door opens, the moment arm (the distance between the center of the shaft and the point on the door that is starting to be wrapped around the barrel) increases. This means that the apparent weight of the door does not decrease as rapidly when it opens. As a result, steel rolling doors typically do not balance well in the middle of their travel. This has to be sacrificed to allow the door to stay down when it is closed and stay up when it is open.
When torsion springs are wound, they grow in length. Since both ends of the torsion springs on steel rolling doors are secured and cannot move, the spring cannot grow in length. There are two options for fixing this problem. You can stretch the spring yourself with a come-a-long before you secure it to the shaft, or your can purchase pre-stretched springs. This allows the coils to be gapped and to lose most of this gapping when the door closes.
It is very important that you order the proper torsion springs for your steel rolling door. The measurements you will need to make must be accurate, or else your door will not operate properly as it did before your spring broke.
There are five characteristics of your broken torsion spring that you will need to determine in order to purchase a new spring. You need to measure the length and wire size of the spring, determine the inside diameter and wind, and identify the type of ends on the spring.
To determine the wire size, you will need to measure the length of 10 coils and of 20 coils. If your spring is gapped in order to keep the coils from binding, you will need to compress the coils to make this measurement. You also need to compress the spring to measure its length, which is the distance from the last coil on one end of the spring to the last coil on the other end. You must compress the torsion spring and not include the gap between the broken pieces of the spring to properly measure your spring.
There is usually a marking on the cones of the spring to identify the inside diameter. If this identification cannot be found, you can measure the space inside the coils. Your spring will either be left or right wind. See our Torsion Spring FAQ's to determine the wind of your spring.
Lastly, you will need to identify how the torsion spring is shaped at the ends. There are primarily two types of spring ends for torsion springs on steel rolling doors. The ends of some springs wrap into the spring cones. If this is the case, you will need to order special straight ends and heat the wire to wrap it into the cones. Other steel rolling doors use torsion springs with a loop at each end. If you have this type of a spring, you will need to order it with steel rolling door loops.
Visit our DIY Instructions page to learn how to measure your torsion springs.
If your steel rolling door has multiple springs, we strongly advise you to replace all of the springs at once. If one spring breaks, there is a good chance that the other springs will break within the next couple of months. Replacing all of your springs at once takes much less time than individually replacing the springs. This will also reducing shipping costs. For more information, visit our Torsion Spring FAQ's page.
Note: If you have multiple springs, you will need to measure each one of them. The springs do not always have the same dimensions, so you will need to determine this for each spring.
Once you have measured your old springs, enter the following information into the form below for each spring:
Once you have entered this information, click Go! to find the price of your replacement springs and to place your order. Be sure to select the correct wind when adding the spring to your shopping cart.