[One of the best] Most popular countersink drill bits set for wood. Bits secured with pin Never Come Loose from shank; Tapered drill bit HSS M2 (Grade 6542), the best High Speed Steel, for its high toughness, wear resistance, and good retention; 4 cutter #45 Carbon Steel; featuring 5 Piece countersink #4 (7/64 inch), #6 (9/64 inch), #8 (11/64 inch), #10 (3/16 inch), #12 (7/32 inch). [Counter Bore]Adjustable 4-flute counter bore, chamfer angle 82 degree, cuts and clears chips quicker for fast, smooth countersinking; the countersink works effortlessly even after many uses; it makes clean and consistent tapered holes for screws without the need of a stop collar. [Tapered Drill] pointed tip with widened design for drilling fast, clean pilot holes and ensures tight fit for screws.Easier to locate the hole and the drill. [Adjusted] counter bore attaches to shank with 2 hex screws can be adjusted for controlled pilot hole depth; Drill, countersink and counterbore in 1 step; the countersink cutter providing superior speed and clean . [Universal Fit]Universal 1/4 inch hex shank prevents slipping in standard chucks and is compatible with all 1/4 inch quick-change chucks, including impact drills of for , for ,for and so on; Hex Key (Hex Wrench) included. Colour: black + silver Material: high speed steel + high carbon steel Package Contents: 5 * Chamfering device 5 * Drill 1 * Hex wrench Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.