Threaded TightFit® drill bits are made of M2 or M7 High-Speed Steel, for use in drilling hard, high-strength alloys and tough, heat-resistant materials. The drill bits have a 135 degree split-point and a 1/4-28 UNF-2A threaded shank. The drill bits are available in three lengths: LONGS = 2 1/8"; SHORTS = 1 1/4"; and STUBS = 1/2-5/8" (threads not included in overall measurement). TightFit® drill bits are black oxided to prevent corrosion while enhancing appearance, and furnished with a 5/16" hex adapter for easy removal after drilling is complete.

To reduce the chance of gear failure and to extend tool life, please follow these suggestions.

1. Reduce RPM speed and drilling pressure at drill "break through".
2. Drill small holes first and then enlarge the holes progressively.
3. Peck drill deep holes to clear chips from the flutes.
4. Coolant use will extend tool life.
5. Re-point drill bits when they become dull.

CAUTION: Always wear safety glasses when using these tools. Do not use TightFit® Drills and attachments counter clockwise (in reverse). Do not exceed 2500 RPM. Keep tools out of the reach of childern.