1. Machine utilizing tooling must have necessary rigidity to minimize spindle deflection and sufficient horsepower to perform at recommended speeds and feeds.
2. Make sure holders and collets give good concentricity between tool and machine spindle.
3. Rigidity clamp and support workpiece to minimize deflection.
4. Use as short a drill as the application will permit to give maximum tool rigidity.
5. Use coolant, as recommended, to improve tool life.
6. Use the correct speeds and feeds to suit the application and material being machined.
7. Resharpen or replace drills at first indication of cutting lip dulling or corner of cutting lip rounding.

Speeds and Feeds for Deep-Hole Drilling

Holes which must be drilled three diameters deeper more fall into the deep-hole drilling class and some adjustments of feeds and speeds is necessary.

The deeper the hole, the greater the tendency there is for chips to pack and clog the flutes of the drill. This increases the amount of heat generated and prevents the coolant from conducting the heat away from the point. A buildup of heat at the point will eventually result in premature failure.

Peck drilling, or the practice of a short distance, then withdrawing the drill, will often reduce the chip packing. The deeper the hole, the more frequent the drill must be retracted to be effective.

A reduction in speed and feed to reduce the amount of heat generated is generally required in most deep-hole applications where coolant cannot be effectively used.