How to Measure Your Torsion Spring

Thank you for choosing W.B. Jones as your spring resource. In this brief guide we will be covering how to measure torsion springs. Please follow these steps closely and do not hesitate to contact us if you have any questions while measuring your springs.

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.

The best way to measure the wire diameter is to use a micrometer and measure the wire in two different spots and then take the average.

For this spring, the wire diameter is .059 inches.

Measure the outside diameter.

Commonly referred to as “OD”. When possible, measure the outside diameter in the middle of the spring because the end coils tend to run large. Since some springs can be small, remember to take your time during each measurement.

The outside diameter of this spring is .682 inches.

Measure the inside diameter.

It is difficult to measure the inside diameter accurately, so use the outside diameter whenever possible. It never hurts to double or triple check your measurements.

For this spring the inside diameter is .565 Inches.

Measure the leg length of the spring.

which is measured from the center to the end like in the picture below. Because the center of the spring is not marked, use your best judgment with this measurement and maybe re-measure it a few times for an accurate reading.

This spring is 1.984 inches long.

Determine the angle or relationship if legs

There are four major angles we’ll cover and they are all based on the center of the spring. Here are diagrams to help demonstrate 90°, 180°, 270°, and 360° relationship of legs. If you cannot determine the angle or relationship of the legs, feel free to contact our staff. We are always happy to help.

90°

180°

270°

360°

Determine the direction of wind.

This part is important with torsion springs because it affects how the spring will rotate in use.

There are two types of wind:

Right Hand wind. Please view the diagram to the left. Notice the way the coil is wound from bottom to top, with right hand springs this follows a counterclockwise rotation.

Left Hand wind. Please view the diagram to the left. Notice the way the coil is wound from bottom to top, with left hand springs this follows a clockwise rotation.

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

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