Johnson 54 Heavy Duty Aluminum Drywall T Square. It has a heavy duty extruded aluminum blade & head with clear silver anodized finish. The blade thickness is 3/16 and it has screened thermal bonded 1/8 graduations in black. It has an exclusive design and solid 4 rivet construction permanently bonds head to blade. Take errors and guesswork out of your next drywall job with this heavy-duty 54 T-square from Johnson. Its extruded aluminum blade and head are a robust 3/16 thick creating a safer straight edge that prevents your utility knife from slipping while its clear protective anodized finish will keep your tool safe from rust and corrosion. The JTS54HD T-square features a unique rivet assembly that permanently bonds the head and blade so that it stays square for life. 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. * Unique rivet assembly permanently bonds head to blade * Head will stay square for life of product * Extruded aluminum 3/16 blade and head thickness * Clear protective anodized finish will not rust or corrode * Screened thermal-bonded black 1/8 graduations * Large bold easy reading graduations