Cobalt Left Hand Drill Bit Set, 29Pcs M35 High Speed Steel Jobber Length Drill Bit Kit for Hardened Metal, Stainless Steel, Cast Iron, Wood and Plastic, with Index Storage Case, 1/16"-1/2"

For so long I went with just whatever came with the drill. These bits are so hard, and with a little bit of oil cuts super well and stays sharp. Left hand is extra handy to drill out broken/welded in screws. Love them. Would bring them to bed if I were allowed.

I cleared a stripped screw head using one of these bits and it took me less than 20 seconds. I had previously tried using several different extractors and none worked. One of these bits was literally the only way I could remove the screw. For note taking purposes, the screw belonged to a door knob and was also warped. I am happy with the quality of all of the drill bits. Mine came slightly lubricated with some kind of machine oil. The affordability of these cobalt drill bits is excellent and their performance is even better. The speed that I was able to remove the stripped screw with was amazing. I literally drilled into it and the lingering stuck knob literally fell off. If all else fails and you're trying to remove a stripped or warped screw, try using these bits to help you out.

Bastante satisfecho con la duración, es similar a las brocas Milwaukee titanio pero a un precio menor para ser de cobalto esperaba que duraran un poco más pero aun así muy satisfecho

Works well

Good quality bits, cut easily and accurately (photo). My usual test for cobalt bits is stainless steel, these bits cut through as easily as mild steel. Run them slow, and dip into water periodically to cool off if you have thick material. It’s also a good idea to use Tap Magic cutting fluid to reduce friction, and thus keep the bits cooler. Good price, happy with purchase.