Common Single Axle Slipper Spring Suspensions will have (2) to (4) of these Bolts per side.
Common Single Axle Double Eye Leaf Spring Suspensions will have (3) of these Bolts per side. Tandem Axle versions of the double eye suspension will have (7) of these bolts per side.
For Reverse Curve Leaf Springs, if they are using 1/2" Bolts, they will have (2) Per side on a single axle suspension, and usually (4) per side on a tandem axle suspension. (Reverse Curve Springs more commonly use 9/16" hardware)