What Is The Hardest Metal To Drill Through?
What Is The Hardest Metal To Drill Through? Cobalt (HSCO) is considered an upgrade from HSS because it includes 5-8% Cobalt blended into the base material. This is a great option for drilling into harder steel as well as stainless steel grades. Carbide (Carb) is the hardest and most brittle of the drill bit materials.