Made of the highest quality cobalt and coated with titanium for longer life. All drills have straight shanks and are finished to drill quickly and cleanly. Benefits: 15 to 1 lifetime over High Speed Steel twist drills. 5 to 1 lifetime over standard cobalt twist drills. More heat resistant than HSS and less brittle than carbide. Work great on rough & uneven surfaces. Drill Set, 10 tubes of 5 ea. Set includes: #50, #53, #56, #57, #60, #64, #67, #70, #72, and #76