Black Oxide Countersink Drill Bit, 5-Piece Set By Irwin Tools (1877791). Product Details Made from industrial grade High-Speed Steel for increased durability. Black oxide finish adds corrosion resistance. Five-flute design reduces vibration for smoother drilling and extended bit life. Precision-ground 82-degree tip drills countersink holes into most machinable metals, as well as wood and plastic. 1/4-inch round shank fits all handheld and stationary drills. IRWIN Tools Black Oxide Countersink Drill Bit, 5-Piece Set (1877791). Made from industrial grade High-Speed Steel for increased durability. Black oxide finish adds corrosion resistance. Five-flute design reduces vibration for smoother drilling and extended bit life. Precision-ground 82-degree tip drills countersink holes into most machinable metals, as well as wood and plastic. 1/4-inch round shank fits all handheld and stationary drills. Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.