How to measure a compression spring
If you need to replace or redesign an existing compression spring, it is critical that you measure all relevant dimensions precisely.
Fortunately, it is a simple process if you follow the correct steps, and it only requires one tool - a calliper. This device is used to take precise measurements of a spring’s dimensions, including its diameter and wire thickness.
Check the spring’s outer diameter
Holding the spring by its outer surfaces, place the calliper’s large outside jaws across the widest points of the spring. Now, use it to measure the distance, which gives you the outer diameter of the spring.
Measure the wire’s thickness
Locate a section of the spring wire that is straight rather than coiled. Position the large outside calliper jaws around the wire, and ensure the jaws are touching both sides.
Record the reading at this location. To ensure accuracy, measure the diameter of the wire at either end of the compression spring.
Measure the inner diameter
Take the calliper’s small inner jaws and insert them into the spring's coil and measure the inner diameter of the spring.
Another way to work out the inner diameter is to subtract the wire diameter (x2) from the spring’s outer diameter.
Measure the free length
Put the spring’s full length (while it is not compressed) between the large jaws of the calliper and take a measurement. This measures the spring’s free length.
Count the number of coils
Finally, place the compression spring on its side, so that it’s flat. Now, count how many coils are on the spring and make sure you include any partial coils.
Do you need made-to-measure compression springs?
As custom spring manufacturers, at SpringXpert, we provide a one-stop shop for the components you require. Bringing specialist spring manufacturing expertise to each order we fulfil, you can count on us for compression springs tailored to the specific dimensions your application demands. Reach out to us now to discuss an order or to make a technical engineering enquiry.