Cobalt drills are an excellent compromise. Harder the HSS drills, less brittle than Tungsten Carbide but can still be sharpened to extend their usable life. Expensive but probably worth the investment.
- Drill out sheared shafts.
- Drill a shaft to use a T-piece.
- Drill out a damaged thread.
- Cheap ones may bend or fracture.
- Can be sharpened to extend usable life.
|1||DEWALT Cobalt Drill Bit Set with Pilot Point, 14-Piece (DWA1240)||441 Reviews||Buy on Amazon|
|2||COMOWARE Cobalt Drill Bit Set- 15Pcs M35 High Speed Steel Twist Jobber Length for Hardened Metal,...||547 Reviews||Buy on Amazon|
|3||Bosch CO14B 14 Pc. Cobalt M42 Drill Bit Set||208 Reviews||Buy on Amazon|