General description High Speed Steel Countersink Drill Bit Set includes 6 pieces with a 1/4'' hex shank, designed for creating 90-degree holes in wood and soft metals. The five-flute design features staggered cutting teeth for efficient chip flow and rapid cutting, making it ideal for countersinking screws and fixings. Technical specifications Material: High Speed Steel Sizes: 6mm (1/4''), 8mm (5/16''), 9mm (3/8''), 12mm (1/2''), 16mm (5/8''), 19mm (3/4'') Length: 48mm (1.88'') Quantity: 6 drills Usage Suitable for wooden planks, fiberboard, particle board, plywood, plastic, aluminum board, and PCB board. Ideal for DIY projects, home improvement, and general building or engineering tasks.