Take the time to properly understanding U-Bolts.
As the name suggests, a U-bolt is a bolt in the shape of the letter U. It has screw threads on both ends, and as U-bolts are used to attach the leaf springs to the axle in your suspension. They are a pivotal component with which you should be very familiar if you intend to do any work yourself.
Frequently asked questions... get up to speed on the basics about U-bolts.
What are U bolts made of?
U-bolts are available in standard sizes or in many cases custom made, manufactured in a range of materials like carbon steel, alloy steel, stainless steel, zinc, fluorocarbon, cadmium and hot dipped galvanized coatings.