They are very sharp and cut through metal very well. I

Cuts like butter through steel. Go slow, use cutting oil, and the bit seems like plenty of life left. Very happy with how sharp the bit was and how well it cut.

Fantastic deal, works great.

Strong driller, drilling stainless steel pot in a few seconds.

Went through my stainless steel sink for a soap dispenser like butter. Absolutely astonishing what you can do with the right tool. Cheap and easy... love it.

Nice design. Used to cut High-Density Plastic. Gut nice and clean. Has spring that pushes piece out.

These bits work best on hardened steel. They are better than cobalt bits for hard materials. They also work on soft materials. They need lots of downforces to cut well; best used in a drill press.

I've been trying to torture test these except my test materials all got easily drilled through cleanly. No apparently dullness even after extended drilling through hardened steel.

I don't know about this kind of stuff but my husband does and needed them.

This is an awesome set of drills. It's all that it is cracked up to do. I am planning to get a second set for my brother who works with all types of metal including stainless steel.