ToolShed Countersink Drill Bit 8 or 10 Gauge. The ToolShed Countersink Drill Bits are available for both 8 and 10 Gauge options, designed for precision and efficiency. This high-performance countersink bit features an adjustable low friction ball bearing depth stop, allowing for accurate control, ease of use and constant countersunk screw holes during your projects. The quarter-inch hex drive is compatible with most drills on the market, ensuring versatility and convenience. Extra-wide gullets are integrated into the design to prevent material jamming, while a rubber O-ring on the bottom of the stop collar prevents marking your work surfaces. Constructed from High Speed Steel (HSS), these countersink drill bits offer exceptional speed and endurance. Each package comes with an extra replacement drill bit, ensuring you're always prepared. Features. - Adjustable low friction ball bearing depth stop for accurate control and ease of use. - Has a quarter-inch hex drive to fit most drills on the market. - Features extra-wide gullets to prevent jamming material. - Rubber O-ring on the bottom of the stop collar will prevent marking your work. - Constructed of High Speed Steel (HSS) for speed and endurance. - Comes with an extra replacement drill bit included. Specifications. 1/4in Hex Drive. 10 Gauge - 3.5mm screw shank size | 9.5mm screw head size. 8 Gauge - 3.2mm screw shank size | 8mm screw head size