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.

What is the hardest drill bit you can buy?

For drill bits, the tungsten carbide is the hardest available for consumers. It will hold its edge longer than the aforementioned metals. However, it is even more brittle than cobalt alloy, so the tungsten carbide is generally used on the tip of steel drill bits instead.

Are carbide drill bits worth it?

Carbide bits can be used to drill already hardened steel. But they are brittle and tend to break if you’re not real careful. They will outlast high speed steel bits four to one so they are worth the little bit extra they cost.