Axle or foot pegs are used in freestyle BMX diciplines such as grinds, air tricks and flatland tricks.
Short 3 to 5 inch long tubes. Street pegs used for grinding tend to be made of chromoly. Some street pegs designed for lightness will either have a thinner chromoly sleeve over an aluminum body. Flatland pegs tend to be made of aluminum, have a larger diameter than street pegs, and have grippy surfaces for the feet.