Guide to Measuring Compression Springs

Thank you for considering W.B. Jones as your spring resource. In this brief guide we will be covering how to measure compression springs so that you will be well equipped to order your desired product.

Tools we recommend you have before you start are:

  • A micrometer, which should be used whenever possible
  • Calipers
  • A ruler or tape measure for large springs

Measure the wire diameter.

We recommend that you measure the wire diameter in two different spots using a micometer and take the average. This will allow for precise readings and accurate ordering.

For this spring, the wire diameter is .253 inches.

Measure the outside diameter.

This is commonly referred to as “OD”. When possible, we recommend you measure the outside diameter in the middle of the spring because the end coils tend to run large.

The outside diameter of this spring is 2.897 inches.

Measure the inside diameter.

This is also known as “ID”. The inside diameter for many springs can be hard to measure accurately. We recommend that you use the outside diameter whenever possible when filling out our online form. Using inside diameter can often lead to inaccurate readings which result in incorrectly ordering your desired spring.

For this spring the inside diameter is 2.381 inches.

Measure the length of the spring.

We’ll use a ruler for this spring, but if your spring is smaller, we recommend using a micrometer or calipers.

This spring is 10.125 inches long.

Find the coil count.

There are two best practices to find the coil count that will lead to accurate measurements of the spring.

Counting the coils.

When doing a coil count, make sure you count each full rotation and then the remainder of the last coil, for example ending with 0.25 inches, 0.5 inches, 0.75 inches, etc.

Measure the space between the coils.

We recommend this method because it leads to the most accurate results. It is best to measure the space in two spots towards the center of the spring and take the average.

The space between the coils for this spring is .621 inches.

You may notice a pitch option when filling out our online form. We don’t recommend using the pitch because it is very subjective.

Now you will have all the information required to measure your compression spring accurately.

Thank you for reading our tutorial and if you find yourself holding a spring-like the one to the right or something not easily measurable or describable, we have members on staff who are always here to help.