Features: brand new and high quality ●This set of size drills has a high-speed steel quality grade that meets the required specifications. HSS M2 grade 6542 is harder than 4241 HSS and 4341 HSS used in other similar countersink drills. ●The depth-adjustable tool countersink is made of high-speed steel with a chamfer of 82 degrees, which cuts and removes chips faster, realizing fast and smooth countersinking; even after multiple uses, the countersink can work effortlessly ; It can make a clean and consistent tapered hole for the screw; the black oxide finish coating enhances corrosion for protection; the universal 1/4 inch hex handle prevents sliding in the standard chuck, and is fast with all 1/4 inches for replacement chucks, including percussion drills. ●The high-quality counterbore is fixed on the flat surface of the shank by 2 hex screws to ensure a firm fit and can be adjusted to control the depth of the pi-lot hole; one-step drilling, countersinking and countersinking; countersinking tools provide excellent speed and Clean surface ●The tapered drill tip with a wide groove can quickly drill a clean hole and ensure a close fit with the screw; the tapered drill bit can be replaced with a replacement drill bit of the same type and size (sold separately) to extend the service life; ●One of the most popular woodworking adjustable countersunk drill bits; the drill bit fixed with a pin will never loosen from the shank; high-quality material parts are highly durable: the best high-speed steel, with high toughness, wear resistance and good cutting edges Retention Specifications: Material:High Speed Steel Color ：Black Size: Approx.15x9x2cm/5.90x3.54x0.78inch Package Includes: 9xCone Drill note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.