FINDING THE INSIDE DIAMETER (ID) OF A TORSION SPRING
The next step in measuring torsion springs is to determine the inside diameter (ID). With a tape measure or caliber, measure from inside spring coil to inside spring coil. The resulting measurement is the diameter of the spring. Measurements should be completed in inches and measured to 1/16” for accuracy.
If the spring you are measuring has spring fittings installed (cones or drums), you can verify the ID by looking for numbers that are etched into the hardware. For example, a 175 will be visible on spring fittings for 1-3/4” ID torsion springs. Generally, the torsion spring ID is a standard width. Refer to the chart below for a listing standard torsion spring inner diameters.
FINDING THE WIRE SIZE OF TORSION SPRINGS
The final step in measuring a garage door torsion spring is to determine the wire size of the garage door spring. Wire size can be measured by using a spring wire gauge, pocket wire gauge or a good ‘ole math formula. All three methods are simple and accurate at giving you the wire size of a torsion spring.
If you are using a spring wire gauge, insert the wire gauge into the spring and count twenty (20) coils. Once you have reached the twentieth coil, look at the numbered markings on the wire gauge to determine the wire size.
If you are using a pocket wire gauge, you can find the correct wire size by matching the correct coil key to your wire size.
If you don’t have a spring wire gauge or a pocket wire gauge, you can always use this trusted math formula to find the wire size of the torsion spring. To get started count 10 or 20 coils on the torsion spring. Measure the coils with your tape measure. Take the measurement and then divide by the number of coils you counted (10 or 20). The answer to the equation would be the wire size for the spring you just measured. Measure to the nearest 1/16 of an inch.
10 COIL EXAMPLE:
10 Coils = 2-7/8 (2.875) Inches
2.875 / 10 = 0.289 Wire Size
20 COIL EXAMPLE:
20 Coils = 5 Inches
5 / 20 = .250 Wire Size
You can also use the chart below to convert the length of coils into the wire size without doing the math.
SPRING WIRE CHART
ARE YOU VISUAL LEARNER? TRY SSC SOLUTIONS EDUCATION
SSC has spent more than 10 years developing an online video training platform to help professional garage door installers and dealers learn the in’s and out’s of the industry. Our INT05:Measuring a Spring Course includes the information above in an easy to follow instructional video followed by short quiz that can be submitted to IDEA for CEU credits. Additional instructional videos with a variety of topics including introductory courses, residential and commercial installations, customer service and management are all available for free to SSC customers.
TRY OUR SSC SPRING ENGINEERING APPS
SSC offers a smartphone app available for Apple & Android Devices and a Desktop App PC & Mac to assist you to quickly determine the garage door spring you need. Our engineering app help take out the the need to measure a spring. Simply put in a few pieces of information and the app will provide you with the size spring you need for the garage door you are working on. Our spring engineering app also offers additional tools to help you with a variety of garage door issues from determining the proper wind of the garage door spring to the cable length needed and more. Check it out today.
ORDERING TORSION SPRINGS FROM SSC:
When you reach out to SSC, you’ll need to have the following information on hand to ensure that your new springs are the correct size. Our sales team can assist you in determining if you can you a stock torsion spring size or if you’ll need a custom made torsion spring to meet your needs. The proper measurements of spring wind, length, inside diameter and wire size will help our sales team assist you in finding the torsion springs that you need.