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 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.