Carbon steel, heat treated construction * Suitable for drilling holes in wood, thin alloy, and thin sheet metal * Well organized in a convenient plastic storage case * Sizes: 3/4", 7/8", 1-1/8", 1-1/4", 1-1/2", 1-3/4", 2", 2-1/2", 3", 3-1/2", 4", 5" hole saws