Irwin Tools 1877720 Countersink Drill Bit, Black Oxide, 3-Piece Product Details Part Number: 1877720 Item Weight: 4 ounces Product Dimensions: 1 x 3.6 x 5.2 inches Origin: China Item model number: 1877720 Size: EA Material: High Speed Steel Item Package Quantity: 1 Batteries Required?: No Shipping Weight: 4 ounces Date First Available: March 13, 2014 Precision-ground 82 tip for countersinking into most machinable metals, wood or plastic Made from industrial grade high speed steel for increased durability Includes a black oxide finish for added corrosion resistance Five flute design reduces vibration for smoother drilling and extended life 1/4" round shank fits all handheld and stationary drills IRWIN High Speed Steel Countersinks feature a precision-ground 82-degree tipthat makes them ideal for countersinking into most machinable metals. They'remade from industrial grade high speed steel for increased durability and theyinclude a black oxide finish for added corrosion resistance. The five flutedesign reduces vibration for smoother drilling and extended life. Plus, the1/4" round shank fits all handheld and stationary drills. From the Manufacturer IRWIN High Speed Steel Countersinks feature a precision-ground 82-degree tipthat makes them ideal for countersinking into most machinable metals. They'remade from industrial grade high speed steel for increased durability, and theyinclude a black oxide finish for added corrosion resistance. The five flutedesign reduces vibration for smoother drilling and extended life. Plus, the1/4" round shank fits all handheld and stationary drills.