NO BURNING OR MARRING: The countersink drill bit includes an adjustable, low-friction revolving depth stop that creates clean hole edges without scratching or burning the surface IDEAL FOR DRILLING: Acrylic, Aluminum/Non-Ferrous, Aluminum Composite Materials (ACM), Composite Decking Materials, Chipboard, Man-Made Boards, MDF, Natural Woods, Plywood 82 DEGREE COUNTERSINK DRILL BIT SET DIMENSIONS: 55295; 1/2 Diameter x 9/64 Drill Diameter x 1/4 Inch Quick Release Hex Shank; slow spiral, HSS M2 fully ground drill bit included CARBIDE TIPPED: Amana countersinks ensure long-lasting cutting edge performance and tool life, delivering repeatable precision for a variety of cutting projects INDUSTRIAL-QUALITY TOOLS: Amana Tool is an industry leader for over 50 years specializing in industrial quality cutting tools for the woodworking, plastics, aluminum, composite, and metal