€¢ Special alloy aluminum extrusion for the blades and tongues of Dry Wall T-Squares. €¢ The toque and blade are attached with four (4) stainless steel rivets to assure permanently set 90° angle. €¢ Numbers and graduations are easy to read. €¢ Dry Wall T-Square are offered in Regular for the Craftsman and Home Owner; and Heavy Duty for the Professional. €¢ The Tooltech FatPat drywall T-square 48in."