Torsion Spring Measurement

Accurate torsion spring measurement is vital. Exact size is imperative.
You absolutely must know and understand the key measurement of your old springs to order replacements. It assumes that the old springs were the correct, to begin with; it is not uncommon to have incorrectly sized springs on a door due to a previous sloppy installation, or a significant change in weight of the door.
You must use springs that matched to the weight of the garage door. You cannot compensate for the wrong size spring by adjusting the number of winding turns.
If you do not know a proper size of the spring, then you must, in turn, have an accurate weight of your garage door.


Step 1: Determine Wind Direction
Look at the end of the spring to determine the wind direction. If the end of the spring points in the clockwise direction, it is a left wound spring. If the end of the spring points in the counter-clockwise direction, it is a right wound spring.


spring-wind

Note: This “right” and “left” has nothing necessarily to do with whether the spring mounted on the left or right of the center bearing plate. With the standard door, if you stand inside the garage, facing out, then the spring to the left with the red cone is a right-hand-wound spring, and the spring to the right with the black cone is a left-hand-wound spring.

Step 2: Measure Inside Diameter (I.D.)
Measure the inside diameter of your spring with a tape measure or caliper.The spring I.D. may also be stamped on the spring fitting.


Spring_ID
Step 3: Determine Wire Size

Spring’s wire size can be determined by several different tools or techniques. Use of a caliper, micrometer, or wire gauge is common ways to determine a spring’s wire size. If none of these tools are available, you can easily measure how many coils are in 20 inches then divide the number of coils into 20. (Example: 20 ÷ 80 = .250) Or simply measure ten coils of wire to the nearest 1/16th of an inch, and refer to the spring chart below. Important: the spring must be tightly compressed with no gaps with no tension. It’s also a good idea to measure twenty coils as a double check.


Spring_wire

10-Coil Measurement

20-Coil Measurement

Wire Size

in

cm

in

cm

1 3/4″

4.50

3 1/2″

8.99

0.1770

 

1 7/8″

4.76

3 3/4″

9.53

0.1875

 

1 15/16″

4.88

3 7/8″

9.75

0.1920

 

2″

5.08

4″

10.16

0.2000

 

2 1/16″

5.26

4 1/8″

10.52

0.2070

 

2 3/16″

5.55

4 3/8″

11.11

0.2187

 

2 1/4″

5.72

4 1/2″

11.45

0.2253

 

2 5/16″

5.95

4 5/8″

11.90

0.2343

 

2 3/8″

6.02

4 3/4″

12.04

0.2375

 

2 7/16″

6.19

4 7/8″

12.38

0.2437

 

2 1/2″

6.35

5″

12.70

0.2500

 

2 5/8″

6.67

5 1/4″

13.34

0.2625

 

2 3/4″

6.93

5 1/2″

13.87

0.2730

 

2 13/16″

7.19

5 5/8″

14.38

0.2830

 

2 7/8″

7.34

5 3/4″

14.68

0.2890

 

2 15/16″

7.49

5 7/8″

14.99

0.2950

 

3 1/16″

7.79

6 1/8″

15.57

0.3065

 

3 1/8″

7.94

6 1/4″

15.88

0.3125

 

3 3/16″

8.12

6 3/8″

16.23

0.3195

 

3 5/16″

8.41

6 5/8″

16.81

0.3310

 

3 7/16″

8.73

6 7/8″

17.46

0.3437

 

3 5/8″

9.21

7 1/4″

18.42

0.3625

 

3 3/4″

9.53

7 1/2″

19.05

0.3750

 

3 15/16″

10.00

7 7/8″

20.01

0.3938

 

4 1/16″

10.32

8 1/8″

20.63

0.4062

 

4 7/32″

10.71

8 7/16″

21.43

0.4218

 

4 5/16″

10.93

8 5/8″

21.87

0.4305

 

4 3/8″

11.11

8 3/4″

22.23

0.4375

 

4 17/32″

11.51

9 1/16″

23.02

0.4531

 

4 5/8″

11.72

9 1/4″

23.44

0.4615

 

4 11/16″

11.90

9 3/8″

23.81

0.4687

 

4 7/8″

12.45

9 3/4″

24.89

0.4900

 

5″

12.70

10″

25.40

0.5000

 

5 5/16″

13.49

10 5/8″

26.98

0.5312

 

5 5/8″

14.29

11 1/4″

28.58

0.5625

 

6 1/4″

15.88

12 1/2″

31.75

0.6250

 


 

  • Step 4: Measure Length of Spring

Use a tape measure to measure the length of the spring to the nearest half of an inch. Measure springs only when relaxed, because the winding adds significant overall length while reducing the coiled diameter. If you have a paired design, and one is broken and one is intact, then don’t try to measure the length of the intact spring with the door down. A wound spring has 7 o 8 turns adding to the overall length, and will therefore be about 2″ longer than when relaxed. Measure the lengths of the broken spring, which will be unwound, and add them together. Measure spring only, do not include length of winding and anchor cones.


spring_length

 

  • Write down the spring size in this format: wire size x I.D. x length
  • ex. : 0.207 x 1.75″ x 22″

  • Replacing garage door torsion springs is dangerous because the springs are under tension. If you do not use the right tools and follow safety procedures, you could lose hands, limbs or even life. You could also damage property. Doing the job right is your responsibility. If you have any doubts – hire a professional to repair your garage door.

 

Posted in Garage Doors Parts.

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