How to Properly Measure a Garage Door Torsion Spring
STEP 1: Determine Wind Direction
STEP 2: Measure Inside Diameter
Step 3: Determine Wire Size
WIRE SIZE: A spring's wire size can be determined by several different tools or techniques. Use of a caliper, micrometer, or wire gauge are 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 amount 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.
Length of 10 Coils | Length of 20 Coils | Wire Size |
1 1/4" | 2 1/2" | .125 |
1 3/8” | 2 3/4" | .135 |
1 7/16” | 2 7/8” | .142 |
1 1/2" | 3” | .1483 |
1 9/16” | 3 1/8” | .1562 |
1 5/8” | 3 1/4" | .162 |
1 11/16” | 3 3/8” | .170 |
1 3/4" | 3 1/2" | .177 |
1 7/8” | 3 3/4" | .1875 |
1 15/16” | 3 7/8” | .192 |
2 1/16” | 4 1/8” | .207 |
2 3/16” | 4 3/8” | .2187 |
2 1/4" | 4 1/2" | .2253 |
2 5/16” | 4 5/8” | .2343 |
2 7/16” | 4 7/8” | .2437 |
2 1/2" | 5” | .250 |
2 5/8” | 5 1/4" | .2625 |
2 3/4" | 5 1/2" | .273 |
2 13/16” | 5 5/8” | .283 |
2 7/8” | 5 3/4" | .289 |
2 15/16” | 5 7/8” | .295 |
3 1/16” | 6 1/8” | .3065 |
3 1/8” | 6 1/4" | .3125 |
3 3/16” | 6 3/8” | .3195 |
3 5/16” | 6 5/8” | .331 |
3 7/16” | 6 7/8” | .3437 |
3 5/8” | 7 1/4" | .3625 |
3 3/4" | 7 1/2" | .375 |
3 15/16” | 7 7/8” | .3938 |
4 1/16” | 8 1/8” | .4062 |
4 7/32” | 8 7/16” | .4218 |
4 5/16” | 8 5/8” | .4305 |
4 3/8” | 8 3/4" | .4375 |
4 17/32” | 9 1/16” | .4531 |
4 5/8” | 9 1/4" | .4615 |
4 11/16” | 9 3/8” | .4687 |
4 7/8” | 9 3/4" | .490 |
5” | 10” | .500 |
5 5/16” | 10 5/8” | .5312 |
5 5/8” | 11 1/4" | .5625 |
6 1/4" | 12 1/2" | .625 |
Step 4: Measure Length of Spring
Also see simple video below