INTOOHss Cobalt Drill Bits Set 21PCS Triangle Shank,Industry Drill bits with Golden Ratio Tip,

Bought this as a surprise gift for my husband. He absolutely loves it and hasn’t complained about it so far!

Drill bits are great and sharp work extremely well

Drill bits work pretty good. The case came all beat to hell. Opens fine but a pain to close.

Broke a bolt off in an engine block. My usual drill bits would not drill the center out for using an "easy-out" extractror, so I ordered these and they cut the hardened metal that bolt was made of and I was able to get it out.

Not all bits will stay centered at start of drilling and some seem sharper and harder than others

I have other Titanium Bits, and these are the best. I recently had to drill new holes in a 12" Strap Hinge and other such bits didn't make a dent, but these went trough like Butter.

Nice bits for the price, high quality. They drill nicely and seem durable. The case is nice as well

I am a mechanical engineer and I know my drill bits. I have some of the most expensive high end drill bits as I do drilling in heavy steel. I tested one of the bits into a thick piece of structural angle iron. The 135 degree bit angle, with a small slot for shedding the nicely developed small chips, is perfect for slower speed precision drilling. The bit had no problem getting through, and a closeup afterwards showed no visible wear. This will be a nice set of drill bits for higher end drilling in hard steel.I would not recommending getting these bits if all you are doing is drilling into wood, plastic and thin mild steel. These bits would be incredible overkill as they are designed for much more difficult industrial applications. You would be wasting your money. However, if you are a doing serious drilling into cold rolled steel or stainless steel, these are essential because of their incredible hardness.Comparing these to a 29 piece set of other M35 cobalt drill bits, I would say you are getting a bargain at this price. I have paid more for a good set.Con: I hate the metal case. It does not have a real hinge, just a piece of bent metal tab in a slot. See my picture. Every time you open and close the case the tab bends. It will break off in a short time.