Compression Spring Tension
Applications using compression springs choose the correct spring based on both physical dimensions, such as outside diameter, wire diameter, free length, etc and they also have force dimensions such as rate, load, stress, etc. If you have an existing compression spring and are looking to increase or decrease the strength, this article will help you. This will also be important information if you are designing a new application.
Where to Start?
Step 1: Measure your existing dimensions to use for step 2. If you are beginning a new project you will need to know the dimensions you need the spring to fit within.
Step 2: Determine the rate of your existing spring. Enter the dimensions you measured in step one into the Spring Creator Calculator.
Instructions for using the compression spring calculator Click Here.
Manipulating the results you received from the Spring Creator Calculator:
Once we have the rate on the spring we are looking to modify, we will need to determine if we would like the spring to be stronger or weaker. The most useful way to present this to a spring engineer is in percentage. For example, you want your new compression spring 50% stronger than your original compression spring.
Example Calculation Stronger Spring:
Original Compression Spring Dimensions:
PC085-953-10300-SST-3000-CG-N-IN
Closed and Ground
Wire Diameter: 0.085 inch
Outside Diameter: 0.953 inch
Free Length: 3.000 inch
Number of Total Coils: 10.300
Number of Active Coils: 8.30
Wire Type: Stainless 302
Using the stock spring for reference in the Spring Creator Calculator the calculated rate is:
11.960 pounds/inch
For this example we want to increase this spring rate by 50%
Formula (2 Steps)
Step 1:
Rate * percentage in decimals = amount to increase
Step 2:
Amount to increase + original rate = New Stronger Rate
Step 1:
11.960 lb/in * 0.5 = 5.98 lb/in
Step 2:
5.98 lb/in + 11.960 lb/inch = 17.94 lbs/in
See chart below for percentage to decimal conversion
Search for that your new spring in our search finder.
Enter an acceptable range for outside diameter, free length, and your new rate.
For example:
Outside Diam: 0.9 in to 1 in
Free Length: 2.5in to 3.5 in
Rate: 17 lbs/in to 19 lbs/in
Number of Results: 14
If this is too many you can narrow your results by narrowing the search fields.
Choose the spring that works best for you, add it to cart and buy directly online.
Example Calculation Weaker Spring:
Original Compression Spring Dimensions:
PC085-953-10300-SST-3000-CG-N-IN
Closed and Ground
Wire Diameter: 0.085 inch
Outside Diameter: 0.953 inch
Free Length: 3.000 inch
Number of Total Coils: 10.300
Number of Active Coils: 8.30
Wire Type: Stainless 302
Using the stock spring for reference in the Spring Creator Calculator the calculated rate is:
11.960 pounds/inch
For this example we want to decrease this spring rate by 40%
Formula (2 Steps)
Step 1:
Rate * percentage in decimals = amount to decrease
Step 2:
Original rate - Amount to decrease = New Weaker Rate
Step 1:
11.960 lb/in * 0.4 = 4.784 lb/in
Step 2:
11.960 lb/inch - 4.784 lb/in = 7.176 lbs/in
See chart below for percentage to decimal conversion
Search for that your new spring in our search finder.
Enter an acceptable range for outside diameter, free length, and your new rate.
For example:
Outside Diam: 0.9 in to 1 in
Free Length: 2.5in to 3.5 in
Rate: 6 lbs/in to 8 lbs/in
Number of Results: 24
If this is too many you can narrow your results by narrowing the search fields.
Choose the spring that works best for you, add it to cart and buy directly online.
You can apply these same formulas to any spring design you come up with. If you need any further help please email us at [email protected] with your dimensions and needed changes. We would be happy to help you with finding the new spring that works for you.
The spring store is perfect for prototyping any compression springs for application improvements. You can add as many springs to cart to meet the $40 minimum order requirements. Once you know which spring works best for you please come back to use to get impressive discounts on production quantities.
Percentage to Decimal Conversion Chart
| Percent | Decimal |
|---|---|
| 0.1% | 0.001 |
| 1% | 0.01 |
| 2% | 0.02 |
| 3% | 0.03 |
| 4% | 0.04 |
| 5% | 0.05 |
| 6% | 0.06 |
| 7% | 0.07 |
| 8% | 0.08 |
| 9% | 0.09 |
| 10% | 0.1 |
| 20% | 0.2 |
| 30% | 0.3 |
| 40% | 0.4 |
| 50% | 0.5 |
| 60% | 0.6 |
| 70% | 0.7 |
| 80% | 0.8 |
| 90% | 0.9 |
| 100% | 1 |
| 200% | 2 |
| 300% | 3 |
| 400% | 4 |
| 500% | 5 |