Review on 🔧 Precision and Versatility: Explore the Drill America TSC5 8 309 Countersinks by Brandon Plowden

This is a high speed steel so it will dull faster than carbide if you use it on wood (or sheet metal which I wouldn't recommend). However, I bought this to get a perfect 60 degree internal bevel on a piece of PTFE tubing for a 3D printer and for that it works great and can last forever. Cutting PTFE will never dull this tip, so it's included in the tool kit and will be used for a long time.