Drill Bit Coating Types Guide: What Each Coating Does and When to Use It
Drill bit coatings reduce friction, increase hardness, and extend bit life — but only in the right applications. Black oxide resists rust and suits general use; titanium nitride (TiN) stays sharp longer in soft metals and wood; cobalt is alloyed into the steel itself and excels in hard metals; carbide is the hardest option for …