Torsion Springs vs. Extension Springs: What's the Difference?
Garage doors typically use one of two types of springs to counterbalance the weight of the door: torsion springs or extension springs. While both perform the same basic job, they operate very differently.
Torsion springs are normally mounted on a shaft above the garage door and work by twisting to store and release energy. Extension springs are typically installed alongside the horizontal tracks and work by stretching as the door closes and contracting as it opens.
Understanding which system your garage door uses is important when identifying replacement springs, troubleshooting problems, or purchasing garage door hardware.
Torsion Springs vs. Extension Springs: Quick Comparison
Torsion Springs
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Typically mounted above the garage door
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Store energy by twisting
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Operate through a torsion shaft and cable drums
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May use one or multiple springs
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Available in a wide range of sizes and cycle ratings
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Common on residential and commercial garage doors
Extension Springs
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Typically mounted alongside the horizontal tracks
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Store energy by stretching
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Operate through cables and pulleys
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Usually installed as a pair
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Require properly installed safety cables
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Common on many residential garage doors
What Is a Garage Door Torsion Spring?
A torsion spring is a tightly wound steel spring mounted horizontally above the garage door opening.
As the garage door closes, the spring winds tighter and stores mechanical energy. When the door opens, the spring unwinds and releases that stored energy.
The spring applies torque to the torsion shaft, which turns the cable drums located near each end of the shaft. Lift cables wrapped around the drums then help raise the garage door.
Torsion systems may use one or multiple springs depending on the size, weight and design of the garage door.
LEARN MORE: How Do Garage Door Torsion Springs Work?
What Is a Garage Door Extension Spring?
Extension springs operate differently.
Rather than twisting, extension springs stretch and contract as the garage door moves.
They are typically installed on both sides of the garage door, running parallel to the horizontal tracks. As the door closes, the springs stretch and store energy. As the door opens, the springs contract and help lift the weight of the door through a system of cables and pulleys.
Because the springs stretch significantly during operation, extension spring systems should also use properly installed safety cables.
How Long Do Torsion and Extension Springs Last?
Garage door spring life is normally measured in cycles rather than years.
One complete opening and closing of the garage door equals one cycle.
The actual service life of a spring depends on several factors, including:
Spring design and cycle rating
Frequency of garage door use
Door weight and balance
Environmental conditions
Proper installation and adjustment
Condition of the other garage door components
Higher-cycle torsion springs are available for doors that experience frequent use, including busy residential garages and commercial applications.
What Happens When a Garage Door Spring Breaks?
When either type of spring breaks, the spring can no longer provide its share of the force required to counterbalance the garage door.
The door may suddenly feel extremely heavy or become difficult to open.
With a torsion spring, a break is often visible as a gap between sections of the spring coil.
A broken extension spring may appear separated or visibly damaged alongside the track.
Other symptoms can include:
A garage door that will not open
A door that opens only a few inches
An opener that strains or stops
A garage door that becomes crooked during operation
A loud bang coming from the garage
A door that suddenly feels unusually heavy
Continuing to operate a garage door with a broken spring can place additional strain on the opener and other components.
How Do I Know Which Type of Garage Door Spring I Have?
In most cases, identifying the type of spring system is easy.
Look above the garage door.
If you see one or more large coiled springs mounted horizontally on a steel shaft directly above the door, you have a torsion spring system.
If you see long springs running alongside the horizontal tracks on each side of the garage, you most likely have an extension spring system.
Some garage doors use other spring configurations, but torsion and extension systems are among the most common.
Is a Torsion Spring Better Than an Extension Spring?
Neither spring type should be chosen simply because one is considered “better.” The correct system depends on the garage door, available space, hardware configuration and application.
However, torsion systems offer several characteristics that make them popular for modern residential and commercial garage doors.
Because a torsion spring applies force through a shaft and cable drums, the system can provide controlled and balanced movement across the width of the door. Torsion springs are also available in many sizes and cycle-life configurations, making them suitable for doors ranging from standard residential applications to heavy commercial systems.
Extension spring systems are mechanically simpler and continue to be used successfully on many residential garage doors.
If an existing system is being repaired, the appropriate replacement is generally determined by the specifications and configuration of that particular door rather than simply choosing between torsion and extension springs.
Are Torsion Springs and Extension Springs Dangerous?
Both types of garage door springs can store significant mechanical energy and should be handled carefully.
Torsion springs are wound under tension. Extension springs are stretched under tension and can move rapidly if a spring or related component fails.
Extension spring systems should include safety cables running through the springs. A properly installed safety cable helps contain the spring if it breaks and reduces the chance of the spring becoming a dangerous projectile.
Anyone installing, removing or adjusting garage door springs should understand the system, use appropriate tools and follow proper safety procedures.
Homeowners who are not comfortable working with high-tension garage door components should contact a qualified garage door professional.
Can You Replace Extension Springs With Torsion Springs?
In many cases, a garage door can be converted from an extension spring system to a torsion spring system, but this is not simply a matter of swapping one spring for another.
A conversion may require a torsion shaft, cable drums, bearing plates, lift cables, spring mounting hardware and properly sized torsion springs.
The correct components depend on the door’s weight, dimensions and existing hardware configuration.
Because the spring system is responsible for counterbalancing the weight of the garage door, conversion components must be properly selected and installed.
How Do I Find the Correct Replacement Spring?
The replacement process is different for torsion and extension springs.
For a torsion spring, several measurements are required to correctly identify the spring, including:
- Wire diameter
- Inside diameter
- Spring length
- Wind direction
We’ve created a step-by-step guide showing how to obtain these measurements.
LEARN MORE: How to Measure a Garage Door Torsion Spring
Extension springs are commonly identified using specifications such as spring length, diameter and the weight the spring is designed to counterbalance.
Never select a replacement garage door spring based only on appearance. Springs that look very similar can have significantly different operating characteristics.
Frequently Asked Questions
Do torsion and extension springs do the same thing?
Yes. Both systems help counterbalance the weight of a garage door, but they store and release energy differently. Torsion springs twist while extension springs stretch.
Where are torsion springs located?
Torsion springs are commonly mounted horizontally on a shaft above the garage door.
Where are extension springs located?
Extension springs are commonly mounted alongside the horizontal tracks on each side of the garage door.
Does a garage door opener lift the entire weight of the door?
It shouldn’t. A properly balanced spring system offsets most of the garage door’s weight. The opener primarily controls the movement of the balanced door.
Can I use a torsion spring in place of an extension spring?
Not as a direct replacement. Converting between the two systems requires different hardware and properly sized components.
Should extension springs have safety cables?
Yes. Properly installed safety cables help contain an extension spring if it breaks.
Shop Garage Door Springs
G.A.S. Hardware supplies torsion springs, extension springs and professional garage door hardware for residential and commercial applications.
Whether you’re replacing a single spring or stocking springs for your garage door business, proper spring identification is essential for safe, balanced and reliable garage door operation.