Cobalt drill bits are the first step when drilling hardened or unknown steels.

M35 (5% cobalt) is suitable for tougher steels, stainless, and repeated drilling where standard bits struggle.

M42 (8% cobalt) offers higher heat resistance and edge retention for harder, heat-treated, or work-hardened materials.

Run at low speed with steady pressure and cutting fluid for best results.

If cobalt fails to cut, step up to TCT

Tungsten carbide-tipped drill bits for when cobalt isn’t enough.

Designed for extreme materials such as hardened bolts, high-tensile fasteners, security plates, and work-hardened steel. Commonly used by locksmiths, fabricators, and engineers.

Requires precise setup, low speed, and controlled pressure. Not suitable for general steel drilling.

That last line is important – it protects you from misuse.