Newdeli 5 Sizes (#4 to #12) Adjustable Countersink Set with Hex Wrench- Tapered Drill Bits Secured with Pin. Features: 5 models can meet your multiple needs.Super sharp, very reliable, easy to use, and built to perform well in both hard and softwoods.Top-quality material #45 Carbon Steel adjustable four-cutter counterbore, chamfer angle 82 degrees, the attachment that cuts fast and clears chips quicker for fast, smooth countersinking applications.Drill, Countersink and Counter-bore in 1 step. Counter-bore size 3/8 inch, plug size 3/8 inchThe counter-bore feature attaches flats on a shank with 2 hex screws for a secure fit and can be adjusted for controlled pilot hole depth providing a clean finish for more polished final products. Specification: Countersink #4 Bit Diameter 7/64" (2,8mm) , counter-bore size and plug size 3/8", using Adjustable depth stop collar 3/8" Countersink #6 Bit Diameter 9/64" (3,6mm) , counter-bore size and plug size 3/8", using Adjustable depth stop collar 3/8" Countersink #8 Bit Diameter 11/64" (4,4mm) , counter-bore size and plug size 3/8 ", using Adjustable depth stop collar 3/8" Countersink #10 Bit Diameter 3/16" (4.8mm), counter-bore size and plug size 3/8", using Adjustable depth stop collar 3/8" Countersink #12 Bit Diameter 7/32" (5,6mm) , counter-bore size and plug size 3/8", using Adjustable depth stop collar 3/8" Sharp cutter head Accurate positioning, high precision, smooth cutting. Tapered drill pointed tip with widened flutes for drilling fast, clean pilot holes, and ensures a tight fit for screws. Adjustment length Quality buicounterboreore attaches to flats on shank with 2 hex screws for a secure fit and can be adjusted for controlled pilot hole depth. 1/4" Hex Shank Robust and tightly clamped, Compatible with all 1/4 inch quick-change chucks, including impact drills. Drill a guide hole Intall the screw Drill,Countersink and counter-bore in a step Description： Countersink drill bits are used to Chamfer or bevel the edge of a drilled hole such that a Countersunk Head Screw can be seated flush with the material surface. Punching can be done quickly and accurately. The external thread design can help discharge waste when drilling, so as to ensure successful drilling. Package included: 5x Countersink drill bit1x Hex wrench