Irwin 5/8 in. Round Most Machinable Metals Countersink is crafted from high-speed steel with a black oxide coating that provides excellent corrosion resistance. Its 5-flute design helps reduce vibration for smoother drilling, ensuring precision and efficiency. The countersink features a precision-ground 82-degree tip, i for countersinking into most machinable metals. Equipped with a 1/4" round shank, it is compatible with all handheld and stationary drills, making it a versatile tool for various applications. This countersink comes packaged individually on a card for easy handling and storage. Model Number: 12412