M35 Cobalt Drill Bit Set 20PCS(1/16"-1/2") High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal with Index Storage Case

Excellent product. Used already. Well made and worth the purchase.

Great job

Great product.

Cobalt is the best to be able to drive through metal that I have ever used

Nice set of common size cobalt drill bits. Cuts like cobalt should. Using a drill press makes these easy to use. Also used in portable DeWalt battery drill. Would buy again.

Use cutting oil and a slow speed and these drill bits would go through Captain Americas shield like butter !

I used these for drilling out a large bolt. They worked well, though one of the bits broke (I think due to over heating). Would buy again.

I got these to drill holes through thin stainless steel. They worked really well. They have two straight sides on the bottom so they don't spin in my drill. Very tough, went right through without a problem. They come out fairly easy but the car holds them good too. The price was right. I had to cut through the metal slowly but surely.

They cut steel and low on price.

The item description states that these bits are Rockwell 67. The 3/16" bit couldn't drill through a test wood spade bit 3/16" thick with a Rockwell 55 rating! A pre-existing hole of 1/16" from a previous attempt with a tungsten carbide bit did not help the bit drill through. The bit barely scratched the surface. I didn't push the test any further with stainless steel. I'm glad I tried these before ordering the larger sets in both SAE/metric. These bits will not go through tempered steel at 45 or more Rockwell and certainly wouldn't drill anything harder like stainless steel! How did this get on the market?

Case is lighter duty than I'd like but the bits themselves cut like crazy. Good first set for the home machinist. Have used multiple times on hard steel and the seem to hold an edge. Probably wouldn't use them with a hand drill as they may be quite brittle, but fine for the drill press.