Descriptions: Great for Sinking 90 Degree Holes into Wood and Soft Metals Countersunk Screws and Fixings. A Chatter-Free,5 flute designed with staggered cutting teeth aranged to insure free chip flow and rapid chatter free cutting. Ideal for Wooden planks,Fiberboard,Particle board,Plywood,Plastic,Alumiumn Board ,Pcb Board etc. 1/4″ hex shank countersinks are fine for a quick drill. Finish: Titanium Coated Shank: Hex Shank Material:High Speed Steel Size:6mm 8mm 9mm 12mm 16mm 19mm Color:as piuctures show Package Includes: 6pcs/set 5 Flute 90° Countersink Drill Notice： 1cm=0.394inch Please allow a little size error due to different manual measurement. As different computers display colors differently, the color of the actual item may vary slightly from the above images, thanks for your understanding! Quality: The s drill bit is made of high-speed steel, strong and durable. Design: All points are at a 90° angle for compatible with sharp and precise countersinking. The cutting edge is hardened and polished to improve clarity. Chatter-free, five-edge design, and interlaced serrated design ensure free chip flow and fast chatter-free cutting. Purpose: 5-blade chamfering drill, mainly used for wood drilling, reaming, chamfering, screw heads, etc. Ideal for wood, fiberboard, particle board, plywood, plastic, aluminum, PCB, etc. 6 sizes, including 6mm (1/4''), 8mm (5/16''), 9mm (3/8''), 12mm (1/2''), 16mm (5/8'') Drill bit diameter and 19mm (3/4'').