Drillco single flute countersinks should be used when multi-flute countersinks chatter or the hole is too small for a multi-flute countersink to enter. 82 degrees countersink is used for countersinking flathead screws. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. Uncoated tools feature just the base substrate without any additional treatment or coatings and are suitable for a wide range of applications. Round shanks allow use with a wide variety of toolholding systems. Right-hand cut tools have a cutting action that engages when they are run in a clockwise direction.