The Starrett 117C center punch with round shank is 4" long and has a 1/8" (3 mm) diameter tapered point. The punch is made from hardened and tempered steel, which provides wear resistance and strength. The round shank is knurled for grip. Center punches make small dimple marks in a workpiece to help guide a drill bit. Manual center punches have a metal shank with a point and are typically tapped with a ball-peen hammer to mark the material. Automatic center punches have an internal spring mechanism that enables them to mark the material without using a hammer, leaving one hand free for steadying the work. The L.S. Starrett Company manufactures precision measuring tools, metrology and testing equipment, and saw blade products. The company, founded in 1880, is headquartered in Athol, MA.