The PTI HSS Countersink 16.5mm with a 1/4" Shank is engineered to create a precise chamfer around pilot holes, ensuring countersunk screws sit flush. Featuring a 90° angle, this countersink is perfect for cleaning, enlarging, and countersinking holes across a range of materials including aluminum, metal, plastic, steel, wood, and brass. Made from High-Speed Steel (HSS), it offers superior durability and performance, maintaining hardness at high temperatures for faster cutting. The tool also boasts reduced clogging, improved clearance, and chatter-free operation, minimizing mechanical vibration. Key Features: Angle: 90° flutes for accurate chamfering and countersinking Material Compatibility: Effective for aluminum, metal, plastic, steel, wood, and brass Performance: Provides a smooth finish with reduced clogging and improved clearance Operation: Chatter-free with less mechanical vibration Material: Made from HSS for enhanced durability and efficient cutting at high temperatures Shank: 1/4" shank for use with machines and portable tools Brand: PTI