Are you ever unsure which type of spring to use on the job? Whether you're an installer, wholesaler, or manufacturer, understanding the difference between torsion and extension springs — and when to use them — is essential. This quick, go-to guide breaks it all down so you can get the right part every time, without second-guessing.

Torsion Springs

How They Work

Torsion springs are most commonly used on sectional garage doors, both residential and commercial. These springs work by twisting (or “torquing”) along a shaft to store mechanical energy. When the door closes, the spring winds up, storing energy. When the door opens, that tension is released, helping lift the door with minimal effort.

Where They're Installed

Torsion springs are typically mounted horizontally above the garage door opening, centered on the header. However, in some installations, especially with low headroom or high-lift systems, you might find them installed at the top sides of the door.

Specs That Matter

Torsion springs come with two cones attached — a stationary cone and a winding cone. The specs of the spring (especially wire size, inside diameter, and overall length) are determined by the weight, size, and construction of the garage door.
Wire sizes commonly range from .207 to .343, but can be smaller or larger depending on the application. Always make sure to match specs precisely — this isn't the place to mix and match.

Important Best Practices

If you're replacing torsion springs, always replace both, even if only one is broken. Springs installed at the same time wear at the same rate — and using a mismatched pair can lead to imbalance, system failure, or even safety risks.

Extension Springs

How They Work

Extension springs are typically used on one-piece garage doors. These springs work by stretching along the horizontal track when the door is closed. As the door opens, the tension is released, helping lift the door.

Unlike torsion springs, which rotate, extension springs expand and contract linearly. They require safety cables to prevent injury if the spring breaks.

Where They're Installed

You'll find extension springs installed on either side of the garage door, stretching along the horizontal tracks. These doors are more common in regions with milder climates — such as California or Florida — where snow isn't a concern. In snowy areas, the front-facing swing of one-piece doors often becomes obstructed, making them less practical.

Types of Extension Springs

There are a few variations to be aware of:

• P (Plug) – Basic connection type
• SL (Safety Lock) – Built with added safety in mind
• C (C-Hook) – Uses C-shaped hooks for attachment

Each type has its own application and compatibility, so be sure to match the spring type to the door and installation style.

So Which Spring Should You Use?

In general:

• Use torsion springs for sectional garage doors and heavier-duty applications. They offer better balance, durability, and smoother operation.
• Use extension springs for one-piece tilt-up doors, usually found in older homes or warm-weather areas where snow isn’t an issue.

The key is always to check the door style, weight, track configuration, and space constraints before choosing a spring. And when in doubt, refer to the specs — or reach out to your supplier (that’s us!) for guidance.