Leaf springs are made up of long flat pieces of metal that are bound together in a long, flat but bowed unit. This type of car spring was used on most cars and trucks until the mid eighties. They are still used on trucks and vehicles used for heavier duty application since they are particularly effective for that use. Most leaf springs are made out of steel, but today some are made of especially strong composite material. You can get new replacement leaf springs for your vehicle, but you can also probably find leaf springs in decent repair at your local junk yard.