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