Johnson's 16 in. x 24 in. Framing Square is everything a builder needs to get the work done quickly, efficiently and accurately. It includes graduations in 1/8 in., 1/10 in., 1/12 in. and 1/16 in. as well as board foot tables and rafter tables, making it useful for any number of different jobs. And those graduations and tables are permanently stamped so you'll never worry about them fading or wearing. This framing square is constructed of steel with a urethane anti-rust coating that is made to last.