U-bolts, that is, horse-riding bolts, are non-standard parts. They are named for their U-shape. They are threaded to be combined with nuts. They are mainly used to fix tubular objects such as water pipes or sheets, such as leaf springs for automobiles. The way to fix objects is like riding a horse on the horse, so it is called a horse riding bolt.
The U-shape is generally used on trucks and is used to stabilize the chassis and frame of the car. For example, leaf springs are U-bolts to connect.
U-bolts are widely used, mainly for construction and installation, mechanical parts connection, vehicle ships, bridge tunnels, etc.