Also known as screw-machine and stub-length bits, these provide maximum rigidity for drilling straighter holes than jobbers'-length drill bits.

Holes in these bits allow coolant to be run through the tool for more efficient chip evacuation. Use them in CNC machines with coolant-through technology.

For the highest accuracy and longest tool life, these solid-carbide bits are harder, stronger, and more wear resistant than high-speed steel, cobalt steel, and carbide-tipped bits.