You have searched in vain for your spring's reference number: the brand has disappeared, the door is old, or the label is illegible. Rest assured, this is very common and is generally resolved through custom manufacturing. Provided you supply the correct information.
A spring is a precision component: a few millimeters of difference are enough to unbalance the door. This article lists all the dimensions to take, how to measure them, and the errors to avoid. For an overview of the subject, refer to our complete guide to sectional door springs.
Why a custom spring rather than a catalog reference?
Standard references cover the most common doors. But the range of sectional doors is very varied: specific dimensions, panels heavier than normal, discontinued ranges, or doors installed as a custom project by a professional. In these situations, no standard reference matches exactly, and an approximate spring results in a poorly balanced door.
At Mydoors, we manufacture custom springs based on your measurements. You get a part dimensioned for your door, rather than a compromise. Our custom garage door spring product page explains the principle, and the custom 67 mm diameter spring with 6.5 mm wire product page illustrates a frequent case.
Dimensions to take from the spring
Four measurements are essential. The inside diameter, measured from the inside of the coils, corresponds to the shaft clearance. The wire diameter, measured with calipers on a coil, determines the spring's strength. The length of the spring at rest is measured without tension, from one end to the other. Finally, the winding direction (left or right) indicates which side of the shaft the spring mounts on: for a two-spring door, you order one of each.
To determine the winding direction, face the spring and look at the direction the coils rise: this reference is often indicated by a color mark on the tension cone, but this varies by manufacturer. If your spring is broken, bring the two pieces together to reconstruct the total length. The detailed method is explained in our guide how to measure your torsion springs.
Information about the door itself
Spring dimensions are not always enough. To validate the balancing, we need to know the characteristics of the door: width and height of the panel, total weight if you know it, type of panels (steel, wood, insulated), and the presence of a wicket door or motorization. A heavier door panel requires a more powerful spring or a different number of coils.
If the weight is unknown, provide the brand, model, and year of the door, as well as the panel dimensions. A data plate is often stuck to the frame or the first panel. Our article on identifying your door brand shows you where to find it. A photo of the entire installation, including springs and shaft, greatly speeds up validation.
Most frequent measurement errors
The first error is measuring the spring under tension: it is then longer or shorter than its actual length. Always measure without tension, or on the spring once removed. The second error is confusing the inside diameter with the outside diameter: the difference is twice the wire thickness. The third is forgetting the winding direction, which produces two identical springs instead of a left and right pair.
Another trap: relying on the color of the spring. Coatings or rust can hide the original color, and markings vary by manufacturer. Finally, never measure an installed and tensioned spring without securing it: a torsion spring can release suddenly. Simply take visual measurements and wait until you have removed the spring using appropriate tools, such as our tension bar, or have a professional intervene.
From order to installation: what to plan for
Once the dimensions are validated, production is launched and the part is shipped to you. Use this time to check the condition of components that work with the spring: cables, drums, bearings, and pulleys. A new spring on a frayed cable remains a risk. Our custom sectional door cables and our collection of drums and pulleys allow you to renew everything in a single order.
During assembly, replace both springs together, check the alignment of the shaft, and lubricate moving parts with a suitable product, for example, our sectional door lubricant spray. After applying tension, the door should remain in place at half-height without moving up or down. If not, adjust the tension or contact us again.
Conclusion
Ordering a custom spring is not complicated once the measurements are reliable: inside diameter, wire diameter, length without tension, and winding direction, supplemented by the door's characteristics. This rigor ensures correct balancing and preserves the service life of the entire assembly.
Our team is here to validate your measurements before production. Please do not hesitate to send us photos: a check beforehand is better than an unsuitable spring.
FAQ: custom spring
What measurements must be taken?
The inside diameter, the wire diameter, the length of the spring without tension, and the winding direction. The dimensions and weight of the door supplement this information.
Can I measure a broken spring?
Yes. Bring the two pieces together to find the original length and measure the wire and inside diameter on one of them. The cut ends do not prevent these measurements.
Should I order one or two springs?
Most torsion doors use two springs, one wound left and one right. It is recommended to replace them together.
What if I do not know the weight of my door?
Indicate the brand, model, year, and panel dimensions, with photos. We will evaluate the correct configuration together.