Which leaf spring end-type is best for trucks, and which end-type gives you the smoothest riding springs?
There are three basic types: square, diamond point, and rolled.
Square Ends
Square, or constant thickness ends, are great for trucks, terrible for cars. It puts a concentration of all the pressure at the end of the leaf, causing hysteresis.
Diamond Point Ends
Diamond point ends are the same as square cut ends, except some of the excess material has been removed. This gives a better riding spring for trucks.
Rolled and Tapered Ends
In rolled and tapered ends, the thickness of the leaves gradually decrease towards the end of the leaf. The reduced thickness allows for increased flexibility.
Rolled and tapered ends produce the smoothest riding springs. In fact they almost eliminate hysteresis.