This post tells you how to choose garage door torsion springs based on the weight of the door
Garage door torsion springs are sized by wire diameter (d), inside diameter (D), and coil length (L)
Knowing what spring sizes work on your door is tricky
door heights and a 4″ drum
If you have a non-standard combination, check out my garage door spring calculator
Links to a spring product on Amazon are included for most sizes for your convenience
preload)TORSION SPRING CODE[d-D-L]Spring Life[cycles]85 lb170 lb207″-2″-23″21k90 lb180 lb180 lb207″-2″-22″ 207″-1- 3/4″-25″17k18k100 lb195 lb195 lb205 lb205 lb207″-2″-20″218″-2″-26″218″- 2″-25″ 225″-2″-29″13k23k19k29k105 lb210 lb218″-2″-24″17k110 lb220 lb218″-2″-23″225″-2″-27″14k21k115 lb 230 lb218″-2″-22″225″-1-3/4″-29″12k17k120 lb235 lb240 lb225″-2″-25″218″-2″- 21″15k10k125 lb245 lb245lb250lb225″-2″-24″207″-1-3/4″-18″234″-2″-29″14kshort20k130 lb255 lb 260 lb260 lb234″-2″-28″225″-2″-23″243″-2″-33″18k12k26k135 lb265 lb270 lb270 lb225″- 1- 3/4”-25”225”-2”-22”243”-2”-32”10k10k23k140 lb285 lb250”-2”-35”27k145 lb285 lb218 “- 1-3/4″-20″ short150 lb300 lb305 lb243″-2″-29″243″-1-3/4”-32″16k15k155 lb310 lb250 “- 2″-32″18k160 lb320 lb250″-2″-31″16k165 lb330 lb250″-2″-30″15k170 lb340 lb250″-2″- 29″ 13k175lb350lb355lb250″-1-3/4″-32″250″-2”-28″12k12k
and has four spring options on the chart: 207″-2″-20″, 218″-2″-26″, 218″-2″-25″ and 225″-2″-29″
and optimally takes a dual spring configuration for balance
The chart offers two size options: 207″-2″-22″ and 207″-1-3/4″-25″, both with similar life
(A single spring setup with 250″-1-3/4″-32″ or 250″-2″-28″ may also work )
Spring Size Chart – 8ft
Spring Size Chart – 8ft
This table lists the proper torsion springs by door weight for an 8-ft
This table lists the proper torsion springs by door weight for an 8-ft
tall garage door
tall garage door
The table lists the weights for both a single and double spring configuration
The table lists the weights for both a single and double spring configuration
SPRINGBYDOORWEIGHTDoorWeight(Singlespring)[lb]DoorWeight(Dualsprings)[lb](8ft door, 4in drum, 8½ t
SPRINGBYDOORWEIGHTDoorWeight(Singlespring)[lb]DoorWeight(Dualsprings)[lb](8ft door, 4in drum, 8½ t
preload)TORSION SPRING SIZE[d-D-L]Spring Life[cycles]95 lb195 lb207”-2”-23”13k100 lb205 lb200 lb207”-2”-22” 207”-1- 3/4″-25″11k12k110 lb225 lb220 lb207″-2″-20″218″-2″-26″7k14k115 lb230 lb230 lb 218″-2″- 25″225″-2″-29″13k17k120 lb240 lb218″-2″-24″11k125 lb250 lb218″-2″-23″225″ -2″-27″ 9k13k130 lb260 lb218″-2″-22″225″-1-3/4″-29″7k11k135 lb270 lb275 lb225″-2″- 25″218″- 2″-21″10kshort140 lb280 lb225″-2″-24″207″-1-3/4″-18″234″-2″-29″8knone13k145 lb 290 lb234”-2”-28”225”-2”-23”12k6k150 lb295 lb305 lb243”-2”-33”225”-1-3/4” -25”16kshort 155 lbs 305 lb225″-2″-22″243″-2″-32″short14k160 lb320 lb325 lb250″-2″-35″218″-1-3/4″- 20″16knone170 lb340 lb345 lb243″-2″-29″243″-1-3/4″-32″10k9k175 lb350 lb250″-2″-32″12k180 lb 365 lb250″-2″-31″11k190 lb375 lb250″-2″-30″9k195 lb390 lb250″-2″-29″7k200 lb395 lb400 lb250″-1-3/4″-32″250″-2″-28″6k6k
How accurate is the weight classification?
The weight of the garage door must be within +-5% of the value of the boards
How do you calculate life in the spring?
The cycle life of the springs is calculated using the fatigue curves for the steel used in the door springs
I derived the fatigue curves (also S–N curves) from the manufacturers’ spring ratings
Actual spring life will vary +- 30% around nominal value
Please also see my post on spring clothes
Can garage door springs be too strong?
Garage door springs can be too strong (or too weak)
If the springs don’t accommodate the weight of the door, they won’t work: they can’t be tensioned to balance the door evenly during its travel
Spring stiffness is the key, not ultimate strength
Spring stiffness, or spring rate, determines the amount of torque and lift the spring gives per revolution
Can I use a heavier spring on my garage door?
You can use a heavier spring on a garage door if the spring stiffness is the same
Such springs would have the same weight rating in the table above
You can also check the IPPT (Inch-Pounds Per Revolution) specification of the springs match
Different weight springs can (perhaps surprisingly) have the same stiffness
If a spring is longer and made of thicker wire, it can have the same stiffness as the original
Should I use one or two torsion springs on my garage door?
The lighter doors have one spring, the heavier ones have two
tall and less than 175 pounds, can be balanced with a standard spring; if over 175 pounds you will need two
If your door weighs around 170…175 lbs or 195…200 lbs, you can choose to use one or two springs
Dual springs will cost more but provide a longer lifespan
Adding a second spring to a working single spring door never works
When changing from one to two springs, you must change the type, see the tables above
The options are summarized in the following table:
It carries a 175 lb spring
or less 200 lb or less Two springs 170 lb