The steel frames are painted with 2 coats of oil-based paint and fabricated from 1/4-inch thick steel. To attach the legs to concrete, you can order the benches in 2 ways to fit your needs:
Extra-Long Legs Option (30" long legs to allow you to place in ground with concrete)
Bolt-Down Legs Option (all hardware included)
Extra-Long Legs Option: If you are going to pour fresh concrete, this option has 30" long legs beneath the benches so you can set them in concrete 18" deep.
Bolt-Down Legs Option: If you have an existing pad already in place, this option comes with a folded steel base with pre-drilled holes so you can bolt the legs to your existing flooring.