Maudlin Products supplies various styles of spring energizers into an array of applications worldwide. Each spring has its advantages and disadvantages in a given application so deciding which system parameter is most important is the key to a good spring choice. For instance, if low friction is critical, a Slant Coil spring will be a better choice than a Helical spring. There are two springs however that are similar in function and it is not as clear when to choose one over the other. These springs are the V-Spring and the U-Spring. The differences are subtle and even when looking at the final forms of each spring (see below) it is difficult to tell which is which but if we dig a little deeper, some difference begin to present themselves.

V Spring

The V-Spring’s legs are far more angled allowing for greater interference and a wider load range. This also allows for greater wear on the seal jacket while still maintaining some amount of spring force.

U Spring

The U-Spring has legs that are almost parallel with a large inside radius which allows for lower initial interference with the hardware and potentially easier installation, particularly if the seal is to be installed lip first.
So what does this mean in terms of choosing one spring over the other in an application? Generally speaking, more interference is a good thing. It can help with inconsistencies in the hardware as well as tolerance stackup issues. Greater interference however can make for difficult installation especially if installing over threads, splines, keyways, square corners, etc. If installation is a known issue, the U-Spring may be the better choice. It produces similar loads to those of the V-Spring but with less deflection. The downside is that with jacket wear the U-Spring seal will run out of spring force more rapidly than a spring with a greater deflection range like the V-Spring.
The differences are subtle but understanding the deeper issues in a sealing system can help point you to the best solution for your specific application. Check out our website at for more information on U and V Spring and feel free to use our engineering services to help you make the best spring choice.