3/8″ Drill Bit

3/8″ Drilling Head (WB-338) by Inland (10mm)

DIAMOND CORE DRILLS BY INLAND
Diamond-coated Core Drills have a 3/8″ (10mm) shaft and fit most hand drills and drill presses. Numerous diameters make them valuable for drilling a wide range of materials including glass, ceramic, marble, plastic and fiberglass. For best results, core drills larger than 1/2″ should only be used in a drill press.