I was happy to see the rates were pretty close to the printed spring rate. They all seemed to be around 3% off which isn't bad.
http://www.sicklines.com/tech/spring-rate-printed-vs-measured-ratings/
Spring Rate Printed vs. Measured Ratings
This isnt meant to be an article detailing who has the most accurate springs, but more to bring light to the fact that the spring rate that is printed on the side of your coil spring sometimes isnt as accurate as you might think.
The value on the side of the spring can fluctuate a bit from spring to spring. Certainly there is an accuracy percentage range that all manufacturers aim for. The reality is that most springs do not measure the same as their printed value, so this is more of an educational tip for those who are looking to get the right spring. The measured value can easily be higher or lower than the value printed on your spring.
For example, if the tolerance is set at say 10% for a steel spring from Manufacturer A, then a 350lb spring could measure between 315lb and 385lb. Similarly, a 400lb spring could measure between 360lb and 440lb within these same guidelines. So a 350lb spring could give you the same real spring rate and sag as a 400lb spring! The heavier the spring, the greater the chance for the spring to measure higher or lower given the same percentage tolerances.
We have gathered a small sample batch of springs that we had tested. This sample batch was examined just to illustrate the point that the measured value on the side of the spring isnt always what you think it might be. If you get a few springs (even from the same manufacturer) that all have the same printed value on them, it might be worth your while to check the values of the springs you have verified (or try another spring that has the same value) if youre not getting the sag youre after.
http://www.sicklines.com/tech/spring-rate-printed-vs-measured-ratings/
Spring Rate Printed vs. Measured Ratings
This isnt meant to be an article detailing who has the most accurate springs, but more to bring light to the fact that the spring rate that is printed on the side of your coil spring sometimes isnt as accurate as you might think.
The value on the side of the spring can fluctuate a bit from spring to spring. Certainly there is an accuracy percentage range that all manufacturers aim for. The reality is that most springs do not measure the same as their printed value, so this is more of an educational tip for those who are looking to get the right spring. The measured value can easily be higher or lower than the value printed on your spring.
For example, if the tolerance is set at say 10% for a steel spring from Manufacturer A, then a 350lb spring could measure between 315lb and 385lb. Similarly, a 400lb spring could measure between 360lb and 440lb within these same guidelines. So a 350lb spring could give you the same real spring rate and sag as a 400lb spring! The heavier the spring, the greater the chance for the spring to measure higher or lower given the same percentage tolerances.
We have gathered a small sample batch of springs that we had tested. This sample batch was examined just to illustrate the point that the measured value on the side of the spring isnt always what you think it might be. If you get a few springs (even from the same manufacturer) that all have the same printed value on them, it might be worth your while to check the values of the springs you have verified (or try another spring that has the same value) if youre not getting the sag youre after.
