Starrett 11H-18-4R Combination Square with Cast Iron Head and Black Wrinkle Finish With reversible lock bolt, scriber, spirit level Graduation: No. 4R - 1/8", 1/16", quick reading 1/32", 1/64" Cast iron head with black wrinkle finish Square blade easy-to-read, sharp graduation Bearing surface is accurately ground Cast Iron Head with black wrinkle finish 18-Inch hardened steel machine divided blade Reversible lock bolt, spirit level and scriber Graduation is 8ths, 16ths. Quick Reading 32nds, 64ths