Take errors and guesswork out of your next drywall job with this 48 T-square from Johnson. The JTS48 T-square features a unique rivet assembly that permanently bonds the 1/8 extruded aluminum head and blade, so that it stays square for life, while its clear protective anodized finish will keep your tool safe from rust and corrosion. This T-square was also designed to be easy to use. It features thermal-bonded black 1/8 graduations that are large and bold for easy reading.