Atoplee Industrial Tools 5 Pc Premium HSS 60&Acirc;&deg; Center Drill Combined Drill & Countersink Lathe Mill Tool Set Color: silver Material: HSS Tip angles: 60 It includes sizes: 1/8" 3/16" 1/4" 5/16" 3/8" in tip diameter Quantity: 5pcs HSS Center Drills This listing is for a set of 5 HSS Center Drills. Plain style 60  angle used for producing center holes in workpieces which require  precision drilling or machining between centers. It also used as starter holes to prevent a drill bit from &#034;walking&#034;. Center and spotting drills are traditionally used to make a conical hole  for a lathe center in order to make a starting point for a standard  twist drill, designed to prevent the twist drill from walking. Used for producing center holds in components or work pieces with require machining between centers. Package Included:A set of 5 HSS Center Drills