Twist Drill Comparison

Leading brands of twist drills (1/2” diameter) of M7 plain alloy and M7 Tri-nitrided were tested by drilling a ¼” titanium (6A1 – 4V) annealed alloy. The drills were compared as received and after four re-sharpenings. Speeds and feeds were varied.

– M7 cryogenically treated drills produced 270% more holes than plain M7 did.