Constant Spring Force

Definition: Spring force is measured by the spring rate. Spring rate is also known as spring constant and it is measured by the pounds of force it takes your spring to travel one inch of compressed distance.

What is meant by the spring constant of a spring?

The spring constant is the constant amount of force increase per the increase of distance traveled; meaning that the force is proportional to the amount of travel.

When working on a compression spring design, besides worrying about the spring dimensions being right, you must make sure that those spring dimensions give your spring the right amount of force. If your spring is too strong, it might not allow the spring to travel the required distance versus if the spring is too weak, it might travel and compress past the required distance. So once you’ve got the dimensions down, then you look at your working loads to start making adjustments to match your required spring force/constant.

Working loads are your required loads at loaded height. The loaded height is the length of the spring after a certain distance traveled. For example, if you need a spring to compress 0.25” (inches) under a load of 5 lb (pounds) and the free length of such spring is 0.9”, your loaded height is 0.65” and the spring rate is 20 pounds per inch (lb/in). Below are the formulas and calculations of this examples.

spring force example of a spring compressing and a chart explaining the constant and proportional increase of force and travel

To calculate loaded height

Loaded Height = Free Length – Distance Traveled

LH = FL – x

LH = 0.9 – 0.25

LH = 0.65

To calculate required spring force/rate

Rate = Load ÷ Distance Traveled

k = L ÷ x

k = 5 ÷ 0.25

k = 20

constant spring force example of spring lengths and travel

Compression Spring Finder

Find and buy stock compression springs in two simple steps using Spring Finder. This easy to use search engine makes it easy to find and buy the stock spring you need.

The following simple steps will get you started:

In the basic search, you can enter:

For the advanced search, you must select “Search More Fields”. Here you can enter:

Once you’ve entered your spring’s specifications, click “Search”.

The following are the specifications you can select to organize your search:

Spring Finder Results in Table

Spring Finder Results in Grid View

Extension Spring Finder

Find and buy stock extension springs in two easy steps using Spring Finder. This simple tool makes finding the stock tension spring you need a fast and productive task. Search through over 4,000 designs off the shelf.

The following simple steps will get you started:

In the basic search, you can enter:

To access the parameters in the advanced search, click on “Search More Fields” where the following dimensions will be available:

The fields are not mandatory so you can choose whatever dimension you feel needed and click “Search” once you have done so.

These are the specifications you can organize your extension springs by:

Spring Finder Results in Table

Spring Finder Results in Grid View

Torsion Spring Finder

Find and buy stock torsion springs in two easy steps using Spring Finder. This simple tool makes finding the stock torsion spring you need a fast and productive task. Search through about 1,000 designs off the shelf.

The following simple steps will get you started:

In the basic search, you can enter:

To access the parameters in the advanced search, click on “Search More Fields” where the following dimensions will be available:

The fields are not mandatory so you can choose whatever dimension you want and click “Search” once you have done so.

These are the specifications you can organize your torsion springs by:

Spring Finder Results in Table

Spring Finder Results in Grid View

Conical Spring Finder

Find and buy stock conical springs in two simple steps using Spring Finder. This easy to use search engine makes it easy to find and buy the stock spring you need.

The following simple steps will get you started:

In the basic search, you can enter:

For the advanced search, you must select “Search More Fields”. Here you can enter:

Once you've entered your spring's specifications, click “Search”.

The following are the specifications you can select to organize your search:

Spring Finder Results in Table

Spring Finder Results in Grid View

Constant Spring Force

Definition: Spring force is measured by the spring rate. Spring rate is also known as spring constant and it is measured by the pounds of force it takes your spring to travel one inch of compressed distance.

What is meant by the spring constant of a spring?

To calculate loaded height

LH = FL – x

To calculate required spring force/rate

k = L ÷ x