Bullet_point: ['Countersink cutter may be used in all popular adjustable or micro-stop countersinking units utilizing a 1/4 inch', 'High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance', 'Precision ground to exacting tolerances and form relieved to insure concentricity of 100 degrees countersink angle', 'Threaded shank is for use with threaded-spindle tools, often used in aerospace and automotive applications', 'Through-hole flute style has a single flute that passes through the cutting head to reduce vibration and chip clogging; also called "zero flute"'] (Page 1)