Extension Spring Rate
In the case of an extension spring, initial tension must be taken into the equation. This is an additional force besides the one considered in the spring rate. To calculate the required load, you will first calculate the rate and then add the initial tension. The result will be the required load in order to reach a certain extended length. In the case of spring rate, you must subtract the initial tension from the total load and then divide the result by the distance traveled. To calculate distance traveled, you will also subtract the initial tension from the load and then divide the result by the spring rate. To learn more about initial tension, click here.