High speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance
Round shanks allow use with a wide variety of toolholding systems
Counterboring is the enlargement of a portion of a hole that has previously been formed
The counterbor is a two piece construction, having an integral shank and counterbore cutter, and a pilot that is interchangeable, which provides flexibility in the use of the tool