Quick answer
Spring torque is the twisting force a wound torsion spring applies to the door’s shaft, measured in inch-pounds, which the cable drums turn into the lifting pull that balances the door.
DASMA defines torque as twisting force around an axis. A spring’s torque rate is its IPPT, inch-pounds per turn, and its total is IPPT times the number of turns. The right total balances the door’s weight.
Quick facts
The key facts about Spring Torque, with sources:
Key takeaways
- Torque is the twist a spring puts on the shaft; drums turn it into lift.
- Each turn of winding adds a set amount of torque (IPPT).
- Total torque must match the door’s weight and drum size, or the door is out of balance.
- Too many turns overstresses parts; too few lets the door drift down, says DASMA.
- Setting spring torque is technician-only work.
What spring torque is
Torque is turning force. DASMA defines it as the twisting force around an axis, measured in inch-pounds 1. A garage door torsion spring is a torque machine: when it is wound, it tries to unwind, and that effort turns the shaft it is locked to.
DASMA’s terminology gives the two numbers that describe a spring’s torque. IPPT, inch-pounds per turn, is the torque rate: how much torque the spring delivers to the shaft for each turn it is wound 1.
MIP, maximum inch-pounds, equals IPPT times turns and describes the total torque needed to lift a door from the floor; it is also used for the torque capacity of a wire size at a given cycle level 1.
The drums convert that twist into a pull on the cables. DASMA defines pounds pull as the torque divided by the drum’s moment arm 1.
How torque balances a door
A door has a weight. The cables lift it from the bottom corners, wrapped on drums at each end of the shaft.
The springs, wound to a certain number of turns, push the shaft with enough torque that the pull at the cables roughly equals the door’s weight.
Then the door feels nearly weightless and stays where you leave it.
As the door rises, cable winds onto the drums and the springs unwind, losing torque. A standard drum keeps the same radius, so pull drops as the springs unwind; that suits a sectional door, because more of its weight rests on the horizontal tracks as it opens.
DASMA’s terms for special drums, such as high-lift drums contoured to balance a high-lift door and vertical-lift drums with changing radius grooves, show how drum shape is used to match torque to load 1.
DASMA defines spring balance as the number of turns needed to counterbalance the door’s weight 1.
Pull at cable ≈ (IPPT × turns) ÷ drum radius
IPPT- Inch-pounds per turn of the spring 1
Turns- Winds applied by the technician 1
Drum radius- Moment arm where the cable leaves the drum 1
Pull- Pounds pull lifting the door 1
Concept only, built from DASMA definitions. Never use it to wind a spring.
Source: [1]
Torque terms in DASMA’s vocabulary
| Term | DASMA meaning |
|---|---|
| Torque | Twisting force around an axis 1 |
| Inch-pounds | English unit of torque 1 |
| IPPT | Torque delivered per turn of winding 1 |
| MIP | IPPT × turns; total torque to lift the door 1 |
| Pounds pull | Torque ÷ drum moment arm 1 |
| Spring balance | Turns needed to counterbalance the door 1 |
| Quarter turn | Unit of winding measurement 1 |
Example: how turns build torque (illustration)
A made-up spring with an IPPT of 20, using DASMA’s definition MIP = IPPT × turns 1. Real IPPT values come from the spring maker’s chart; these numbers only show the arithmetic.
| Turns wound | Calculation | Torque (inch-pounds) |
|---|---|---|
| 2 | 20 × 2 | 40 |
| 4 | 20 × 4 | 80 |
| 6 | 20 × 6 | 120 |
| 8 | 20 × 8 | 160 |
Torque rises in a straight line with turns. That is why a technician sets an exact number of turns from the maker’s chart: too few and the door is heavy, too many and it flies up. DASMA says the number of turns should always follow the door maker’s instructions 3.
Where torque shows up for owners
You feel it as balance. A correctly torqued door lifts with little effort and stays put when you let go partway. DASMA’s home inspection checklist asks whether the door stays in the fully open position and in a partly open position 3 to 4 feet above the floor 2.
On paperwork, it appears indirectly: spring sizes and sometimes the number of turns. DDM Garage Doors notes that residential doors with standard 4-inch drums typically carry about eight coils of added length from winding on a 7-foot door and nine on an 8-foot door, because a spring grows about one coil per turn 5.
Torque on two-spring doors
On a door with two springs, the springs share the torque. Each carries about half the load if they are matched. If one spring breaks, the other alone cannot balance the door; it will feel heavy and may drop if the opener is disconnected.
DDM notes that two springs can make a door safer if one breaks while the door is open, because the other can keep it from falling 5.
It also notes many installers mix wire sizes on two-spring doors 5. Mismatched springs can still balance a door if their combined torque is right, but replacement must account for both.
Why drum size matters as much as the spring
The same spring gives a different lifting pull on a different drum. DASMA defines pounds pull as torque divided by the drum’s moment arm, the radius where the cable peels off the drum 1.
A bigger drum radius means less pull for the same torque; a smaller radius means more pull but more turns of the shaft to raise the door.
That is why spring charts are specific to drum type and door height.
A technician cannot swap drums without re-checking the springs, and a high-lift or vertical-lift conversion changes the drums, the springs and the turns together.
DASMA lists high-lift drums contoured to balance a high-lift door, and vertical-lift drums with changing radius grooves 1.
It also explains why cables matter to torque. A cable that has slipped a groove or unwound from one drum changes the moment arm on that side and can tilt the door. See cable drums.
Turns, stretch and coil rub
Torque is not the only thing set at winding. DASMA notes that a torsion spring also needs the right stretch: too little and the coils scrape against each other during operation; too much and the spring can “snake,” which also causes rubbing 3.
Shaft movement side to side can change stretch after installation 3.
Coil rub wears the steel and shortens life, and it can make a squealing or grinding sound. If you hear that from the springs, it is a reason for a service visit, not lubrication guesswork.
Correct torque vs wrong torque
Correct torque
What torque alone cannot fix
Torque cannot make up for a spring that is the wrong size for the door. DASMA warns that applying a spring to the wrong door shortens life and can make manual operation unsafe 3. Adding turns to a weak spring to “catch up” overstresses it and shortens its life further.
It also cannot compensate for a door that got heavier. Paint, glass or added parts can push a door past its springs’ design 3.
What drives the cost of torque problems
No prices on this page. See the cost guide.
- Rebalancing a sound spring set is a short service.
- Replacing worn springs that have lost torque.
- Resizing springs after the door’s weight changed 3.
- Drums or cables worn by running out of balance.
How a technician sets torque
Professional work with winding bars. Described so you understand the visit, not to copy it.
- Confirms door weight, height and drum type.
- Selects springs whose torque suits the door per the maker’s chart 3.
- Winds the specified turns in the specified direction 3.
- Sets the correct stretch so coils do not rub 3.
- Checks balance: the door should hold partway open 2.
Owner checks
- Watch whether the door drifts down from open; that suggests lost torque 3.
- Notice if the opener strains more than before.
- Book a balance check at yearly service; see balance test.
- Never add or remove turns yourself.
Why torque is dangerous to handle
A fully wound torsion spring stores its whole torque, enough to balance a door that can weigh well over 100 pounds.
Releasing it suddenly, through a slipped winding bar or a loosened set screw, can spin hardware with great force.
DASMA warns that excessive torque puts excessive force on other parts and is a safety issue for the installer 3.
Never loosen a winding cone
Do not touch the set screws on the winding cone or try to add or remove turns. The cone holds the spring’s full torque. DASMA says all spring adjustments belong to a trained technician with proper tools 2.
Standards
Spring torque is set by makers’ charts and installation instructions under the voluntary counterbalance standard ANSI/DASMA 103 6.
DASMA TDS-190 tells installers to use the number of turns and direction in the door maker’s instructions 3.
The federal opener rule tells owners to keep the door properly balanced and have springs serviced by a qualified person 7.
Torque vs related terms
| Term | What it is |
|---|---|
| Spring torque | Twist the spring applies to the shaft |
| Wire size | Steel thickness that sets torque capacity |
| Cable drum | Turns torque into cable pull 1 |
| Counterbalance | The whole system offsetting door weight |
| Opener force | Opener’s resistance threshold, unrelated to springs |
Myths about spring torque
- Myth More turns make the door safer.
- Reality Over-winding stresses parts and makes the door fly up 3.
- Myth A weak spring just needs more turns.
- Reality It needs the right spring; extra turns shorten its life.
- Myth The opener provides the lifting torque.
- Reality The springs do; the opener moves a balanced door 4.
Climate and torque
Springs do not gain or lose much torque with temperature, but cold makes doors stiffer and seals grippier, so a borderline balance shows up in winter. Rust in humid or coastal garages weakens springs over time 3.
What this means for you
If the door feels heavy, drifts down or flies up, the torque is off. Book a technician; do not adjust it. When springs are replaced, ask that the door be balanced and tested before the visit ends. See spring repair.
The halfway test tells you a lot
A technician’s balance check, with the door released halfway, shows whether torque is right. Ask to see it.
Questions about Spring Torque
What is torque on a garage door spring?
The twisting force a wound torsion spring puts on the shaft, measured in inch-pounds. The drums turn it into a pull on the cables that balances the door.
What does IPPT mean?
Inch-pounds per turn: the torque a spring adds to the shaft for each turn it is wound, as DASMA defines it.
What does MIP mean?
Maximum inch-pounds: IPPT times turns, the total torque needed to lift a door from the floor, per DASMA.
How many turns does a garage door spring need?
It depends on the door height and drums; the door maker’s chart sets it. DDM notes standard 4-inch drums on 7-foot doors typically add about eight coils of length from winding. Only a technician should wind springs.
What happens if a spring has too much torque?
The door can fly up and be hard to close, and parts are overstressed. DASMA calls excessive torque a safety issue for the installer.
Why does my garage door drift down?
Often the springs have lost torque or were under-wound. DASMA notes insufficient torque can let a door drift down from open. Have the balance checked.
Can I adjust spring torque myself?
No. The winding cone holds the spring’s full torque, and DASMA says adjustments must be done by a trained technician with proper tools.
Do both springs share the torque?
Yes, on two-spring doors each carries part of the load. If one breaks, the other cannot balance the door alone.
Sources
- DASMA Technical Data Sheet #160, Sectional Garage Door Terminology, retrieved .
- DASMA Technical Data Sheet #167, Residential Sectional Garage Door and Electric Operator Checklist for Home Inspectors and Consumers, retrieved .
- DASMA Technical Data Sheet #190, Factors Affecting Spring Cycle Life, retrieved .
- DASMA Technical Data Sheet #385, Opening a Motorized Garage Door to Exit a Home Through the Garage in a Power Outage, retrieved .
- DDM Garage Doors (parts supplier), Garage Door Springs: types, measuring and FAQs, retrieved .
- DASMA, The New DASMA 103 (interview on the counterbalance standard, Door & Access Systems, Winter 1999), retrieved .
- 16 CFR Part 1211, Safety Standard for Automatic Residential Garage Door Operators (eCFR, current), retrieved .
Expert review
Written by the HyreGarage Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Torque vocabulary from DASMA TDS-160; installation factors from TDS-190; balance checks from TDS-167; winding context from DDM Garage Doors; illustrative arithmetic uses invented IPPT, labeled as such.
Suggest a correction. We fix errors and say what changed.