A leaf spring is used for vehicle & trailer suspension. It consists of a stack of slightly curved narrow steel strips which are called "leaves". The curve in the steel allows it to absorb the energy transmitted through the tires by the bumps on the road.

There are two examples of leaf springs:

Double Eye Springs are used with the shackle-type suspensions. Slipper Springs are the heavy-duty springs used with slipper-type suspensions.

There are four main criteria used to select a spring when going on a brand new trailer, or matching to replace an old spring: Width, Free Length, Number of Leaves, Flat Length, Eye Size.

Width: A measurement across the bottom of the spring leaves. Corresponds with the width of the spring seats

Free Length: A measure of the length of the spring from eye to eye ( or eye to end of slipper for a slipper spring)

# of Leaves: A count of the number of strips of steel stacked together. Count at the centre point.

Flat Length: A length measurement which follows the actual contour of the spring. This measure is better than the Free Length measurement because old/used springs "relax" after use. Flat length is measured by taking the length from the centre of one eye to the centre bolt on the sping, repeating on the other side, then adding the two together.

Eye Size: When building a trailer, the eye size of the spring is necessary to select the other hardware pieces that bolt to the spring.

The below image shows you how to measure a leaf spring.

Here is an example of how to keep the measurements to identify the part number needed

Now that you know which leaf spring you need and what measurements to find - Follow the link to find the part number for your leaf spring

If you need any assistance please contact our team via live chat, email, or call 800-300-4067 -hitchweb Team