Specification: Material: Carbon Steel Color: Black Gold Main Part: 8030mm/3.15 1.18 inch Center Drill: 602.88mm/2.36 0.11 0.31 inch Center Drill: 603.28mm/2.36 0.13 0.31 inch Center Drill: 63.510mm/ 2.36 0.14 0.39 inch Center Drill: 604.010mm/2.36 0.16 0.39 inch Shank Diameter: 6.25mm/0.246 inch Description Upgrade Four-Edge Countersink Drill Bit With Touch-Wood Stop Limit Function, Alloy Countersink Drill Bit, Adjustable-Depth Stepped Drill Bit For Hidden Screws, And Countersunk Head Drill Bits Box Contents: This 4pcs Countersink Drill Bit Set includes four high-speed steel (HSS) M2 tapered bits in sizes 2.8mm, 3.2mm, 3.5mm, 4.0mm along with 8mm and 10mm counterbores. The 6.25mm hex shank ensures a secure grip and universal compatibility. Touch-Wood Stop Limit FunctionNewly upgraded countersunk drill, the aluminum ring will immediately stop rotating when it touches the wooden board during operation,reduce wear and prolong lifespan. Depth Adjustable: Achieve precise drilling with our countersink bit set. It features adjustable drill and counterbore depths. Use the included wrench to effortlessly set the depth stop. The plastic collar effectively minimizes surfacing marring. Sturdy: The sharp tungsten - steel alloy can create smooth countersink and counterbore holes. The M2 HSS countersink bit, equipped with chip flutes, ensures swift and efficient cutting. Wide Application: This set is suitable for use with natural woods, chipboard, man - made boards, plywood, MDF, pine decking, drywall, and various plastic boards. Package 1PC Countersink Drill Bit Set for Wood