Garage door torsion springs are made of Oil Tempered (ASTM A229) steel. The strength on a torsion spring is based on the dimensions of the spring. These dimensions are the spring length (overall length not including the cones / fittings), the inside diameter and the wire size. The active coils of the spring is the length of the spring multiplied by the wire size. The wire size is measured in decimal inches. Although it is possible to measure the wire size with a pair of calipers, we have found many individuals get erroneous results for the spring wire size with either a dial or digital caliper. For the average individual it is easier to count 40 coils of the torsion spring and measure that length to the nearest 1/8 of an inch. The decimal wire size is the length divided by the number of coils. The table below show the decimal wire size vs the length of 20 and 40 coils. Garage Door Co Repair Pros recommends using 40 coils to reduce the effect of measurement errors. Although there are "spring gauges" readily available which are based on 20 coils our service techs have been using the 40 coil method described above for many years with excellent success. The color shown in the table are the DASMA standard colors. If the wire is a common wire size it will be indicated with a 'YES' below. All spring measurements are to be performed when the spring is under NO tension.

The above description of measuring a garage door torsion spring is for reference purposes. Garage Door Co Repair Pros ALWAYS recommends that these springs be installed by a trained professional. If you are in the Chicago, IL area (our local service area) please use the contact links above for personal assistance in replacing your torsion springs.

Torsion Spring Wire Size Table, industry color, and length of 20 or 40 coils

Garage Door Torsion Spring Wire Size Table
Wire Size (in) Common Wire ? Color Length 20 coils (in) Length 40 coils (in)
0.1250 NO LT BLUE 2.500 5.000
0.1350 NO YELLOW 2.700 5.400
0.1430 NO RED 2.860 5.720
0.1480 NO BROWN 2.960 5.920
0.1562 NO TAN 3.124 6.248
0.1620 NO GREEN 3.240 6.480
0.1770 NO GOLD 3.540 7.080
0.1820 NO PURPLE 3.640 7.280
0.1875 YES BLUE 3.750 7.500
0.1920 YES ORANGE 3.840 7.680
0.2000 NO LT BLUE 4.000 8.000
0.2070 YES YELLOW 4.140 8.280
0.2187 YES WHITE 4.374 8.748
0.2250 YES RED 4.506 9.012
0.2343 YES BROWN 4.686 9.372
0.2375 NO TAN 4.750 9.500
0.2437 YES GREEN 4.874 9.748
0.2500 YES GOLD 5.000 10.000
0.2570 NO PURPLE 5.140 10.280
0.2625 YES BLUE 5.250 10.500
0.2730 YES ORANGE 5.460 10.920
0.2830 YES LT BLUE 5.660 11.320
0.2890 NO YELLOW 5.780 11.560
0.2950 YES WHITE 5.900 11.800
0.3065 YES BROWN 6.130 12.260
0.3125 YES TAN 6.250 12.500
0.3195 YES GREEN 6.390 12.780
0.3310 YES GOLD 6.620 13.240
0.3437 YES BLUE 6.874 13.748
0.3625 YES ORANGE 7.250 14.500
0.3750 YES LT BLUE 7.500 15.000
0.3938 YES YELLOW 7.876 15.752
0.4062 YES WHITE 8.124 16.248
0.4218 YES RED 8.436 16.872
0.4305 YES BROWN 8.610 17.220
0.4375 YES TAN 8.750 17.500
0.4531 NO GREEN 9.062 18.124
0.4615 NO GOLD 9.230 18.460
0.4687 NO BLUE 9.374 18.748
0.4900 NO ORANGE 9.800 19.600
0.5000 NO LT BLUE 10.000 20.000
0.5312 NO WHITE 10.624 21.248
0.5625 NO RED 11.250 22.500

Torsion spring standard inside diameters by manufacturer

Garage Door Torsion Spring Inside Diameters
Inside Diameter (in) Used By
1 19/32 Crawford
1 3/4 Many mfgs - incl Amarr, Clopay
1 13/16 Barcol
2 Many mfgs  - incl Amarr, Clopay, Overhead
2 1/4 Raynor
2 5/8 Many mfgs  -incl Amarr, Clopay, Overhead
3 1/8 Kinnear
3 3/8 Overhead
3 1/2 Raynor
3 3/4 Many Mfg   - incl Amarr, Clopay
3 25/32 Crawford
4 Wagner
4 1/2 McKee
4 7/8 Rowe
5 1/8 McKee
5 1/4 Many mfgs - common
5 1/2 Ankmar, Raynor
5 3/4 Many mfgs  - common
6 Many mfgs  - incl Amarr, Clopay