Alfa Tools AUG61346 1 x 18 Overall 7/16 Shank Ship Auger Bits Ship Auger Bit - Hex Shank 1-inch Bore Diameter, 12-inch Flute Length 18-inch Overall Length, 5/16-inch Hex Shank Single Twist, Single Cutter, Medium Fast Screw Point Quantity - 3 per Pack