Spring Measurement Guide


Use the following instructions for measuring the dimensions of the spring needed for your specific application. A set of calipers, accurate to at least a hundredth of an inch, is required for several measurements. For more information, contact us.

COMPRESSION   EXTENSION   DIE   TORSION


Compression Spring Dimensions

  1. Hold the base of the spring in one hand, and the calipers in the other hand.
  2. Place the calipers on the outside of the last coil, measuring the largest dimension. This is called the Outside Diameter (O.D.).
  3. Place the calipers on the wire in the center of the spring. This is called the Wire or Material Size. You should also measure the wire toward one end for comparison and accuracy.
  4. Place the calipers on the full length of the uncompressed spring. This is called Free Length.
  5. Count the total coils, beginning at one end, just next to where the wire has been cut. Be sure you count all coils, including any portion of a coil. (see diagram for example)


Extension Spring Measurements

  1. Hold the spring in one hand, and the calipers in the other hand.
  2. Place the calipers across the outside coil, either at the end or the center of the spring. This is called the Outside Diameter (O.D.).
  3. Place the calipers on the wire at one end of the body coil of the spring. This is called the Wire or Material Size.
  4. Place the calipers (or tape measure) on the full length of the spring, inside the hooks. This is called the Length (L.I.H.). (see diagram for example)


Measuring Die Springs

  1. Measure the Hole Diameter (also known as Outside Diameter)
  2. Measure the Rod Diameter (also known as Inside Diameter)
  3. Measure the Free Length (no load on the spring)
  4. Measure the Wire Size (both width and thickness dimensions)
  5. Use our search feature or catalog to find the correct color code and size for your needs.

For example, if a die spring measures .96" on the hole dimension, it will fit into a 1" hole. If it measures .56" on the rod dimension, it will fit over a .50" rod.
Note: Die springs are manufactured to a "GO/NO-GO" dimension.



Torsion Spring Dimensions

  1. Hold the spring in one hand, and the calipers in the other hand.
  2. Place the caliper "teeth" on the inside diameter. This is called the Inside Diameter (I.D.).
  3. Place the calipers on the "leg" to measure the wire. This is called Material Size (or Wire Diameter).
  4. Place the calipers on the working coils of the spring. This is called the Body Length.Place the calipers on the working coils of the spring. This is called the Body Length.
  5. Count the total coils, beginning at one end, just under where the leg leaves the body. Count to the other end, all full coils, and any fraction thereof. This is called Number of Coils and determines leg position. i.e. 90°, 180°, etc.
  6. Determine the direction of coil (Wind Direction). See diagram for hand/finger illustration. Right Hand Wind or Left Hand Wind.