Attention! Input results shown will be +/- 10% from middle value. Hint: The closer your min and max inputs are, the more accurate your results will be!

Attention! Input results shown will be +/- 10% from middle value. Hint: The closer your min and max inputs are, the more accurate your results will be!

Attention! Input results shown will be +/- 10% from middle value. Hint: The closer your min and max inputs are, the more accurate your results will be!

Attention! Input results shown will be +/- 10% from middle value. Hint: The closer your min and max inputs are, the more accurate your results will be!

# The Slenderness Ratio is Making Your Spring Buckle

### Why does my spring buckle or bend?

Compression springs can sometimes be a little wobbly. This creates instability and lack of proper performance because, when they are compressed, this instability is causing them to bend or buckle. Not to mention, that this could also cause it to pop off your device.

### What is the spring slenderness ratio?

The slenderness ratio is the proportion of a spring's coil diameter and free length (think of it as length and width). If the spring slenderness ratio is over 4 then it is likely that your spring will buckle.

When designing or choosing a spring, it is important to consider the spring stability and the position or space your spring will be placed into. The spring slenderness ratio is a key determinant in defining whether your spring will bend or buckle.

### How do I know what is the slenderness ratio of my spring?

To find out what a spring's slenderness ratio is, all you need is two quick and simple formulas. First, you will need to determine the mean diameter of your spring (the diameter in the middle of the outer and inner diameters). Then, you divide the length of your spring (free length) by the mean diameter. If the number you get is greater than four, your spring will bend or buckle.

### FORMULAS FOR MEAN DIAMETER

D = Douter – d
D = Dinner + d
##### Key
• D = Mean Diameter
• Douter = Outer Diameter
• Dinner = Inner Diameter
• d = Wire Diameter

### FORMULA FOR SPRING SLENDERNESS RATIO

Free Length / Mean Diameter = Spring Slenderness Ratio
• Spring Slenderness ≥ 4: the spring will likely buckle
• Spring Slenderness ≤ 4: not likely to buckle or bend

### How do I prevent my spring from bending or buckling?

The good thing is that your spring design can be adjusted to prevent bending or buckling. Below is a list of suggestions to improve your spring's slenderness.

### Tips to Improve Slenderness Ratio

• Increase the outer diameter, decrease the free length or add more coils. More coils will give the spring more stability. Adjusting the outer diameter and free length will change the proportion of your spring's dimensions and lower the slenderness ratio.
• Inserting the spring into a rod or place it in a hole. This will help keep the spring in place and prevent it from popping out of your device.
• Purchasing a compression spring that has a more adaptive shape. Conical springs, barrel springs, and hourglass springs can help you avoid buckling. The shape of such springs prevents them from bending or wobbling when compressed, and makes them ideal for different types of applications.

### Buy the right Compression Spring to reduce buckling issues!

No matter what type of compression spring you are looking for, you can find what you need at Compression Spring. All you need to do is complete a quick search with our Spring Finder. If you are still unsure about what spring to choose or are having trouble finding the right one contact us today at (951) 276-2777.