Drillco Construction or Car Reamers are especially adapted for heavy duty reaming as encountered in the fabrication of structural steel assemblies. They are tapered at the point to facilitate entering of holes which are out of alignment. High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance. Black oxide treatment adds lubricity and creates small pockets on the surface of the tool that act to hold coolant near the cutting edge. Hex shanks have six flats on their sides to reduce slippage when working in high-torque applications. When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging.