Starrett C33HC-12-4R 12-Inch Combination Square with Forged and Hardened Steel Head With reversible lock bolt, scriber, spirit level Graduation: No. 4R - 1/8", 1/16", quick reading, 1/32", 1/64" The square heads are forged hardened steel with smooth black enamel finish Square blade easy-to-read, sharp graduation Square head and center head bearing surface are accurately ground 4R Grad: 8ths, 16ths, Quick Reading 32nds, 64ths Smooth Black Enamel Finish Center Head Satin Chrome Blade