MACXCOIP Cobalt Drill Bit Set, 13Pcs 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"-1/4"

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.

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.

The drill set is as shown . The metal housing is damaged from shipping. The tiny brass hinges are weak and broke and the inside bent. The drill bits themselves are fine.

I had a use case where a machine screw had broken off in a location that wasn't easy to access. I decided versus pulling the piece of equipment apart to improve access, I'd spend the money on a set of these with the hopes it would catch as I was drilling out the broken off screw. The screw broke during installation, so I wasn't worried about rust or anything like that, and the roll of the dice paid off. As I slowly increased the size of the bits, one finally caught and backed it out. I replaced the machine screw with a new one and job done. This set saved me about an hour of disassembly and for me, that made the set worth the price. I don't know long-term how they'll hold up, but for me, these will be used infrequently and as I mentioned, they've already paid for themselves, so future use is just money in the bank. The case is nice and the quality seems good, so no regrets here.

Solid drill bits that cut really well

Took a chance on these cobalt bits because of how many sizes it includes for the reasonable'ish price. The problem is that the quality is very shoddy. The round ends that spin in your chuck are annoying, but over half of the bits I've used so far chip and break instantly upon first use. I'm drilling annealed un-heat treated 1095 steel. My name brand cobalt bits go through like butter, but these... Some of the bits work fine so far, but it's been more miss than hit. I guess it's nice to have all the odd sizes that are included,and they'd probably work on soft materials, but these are made for drilling metal, and they ain't cutting it.

Surprisingly effective and durable when combined with cutting fluid

If you. Break a bolt off in an engine block this is invaluable. Help get my BMW back on the road.

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.

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

I purchased this particular set because I needed a #30 wire gauge drill bit for a project that used 1/8" rivets . The only other option for a SINGLE bit on Amazon was stuck in "neverland" and other sites wanted $30USD for a single bit which was not reasonable. So I found this set for a good price rather than buying them singly. I am significantly impressed with the quality and strength of these bits on 550 stainless and lubricant... Though my unsteady hand meant some failed starts and controlled rpms on my hand drill. (These are probably better on a drill press). Starting the hole was easy enough as was finishing through the mixed materials and the bit did not overheat or wear. I cant say about Cast Iron or Titanium though but your mileage may vary. These would go through pretty much anything else easily as long as you had the right lubrication and Pressure/RPM control. ALL small bits (and these are all smaller than 1/4 of an inch) will break easily so just be mindful of that and go slow and steady without overt amounts of force. The bits are all neatly organized in its index and a small pull tab brings them out as well. Each bit is labelled as is its index for easy use. My only complaint (and I took a star off for this) is that the front label is upside down with no indication or sticker as to which side goes up. Otherwise I had to open my bit box on its side so they didn't all spill out on my table (thanks to reading reviews). I think these are factory rejects because of the label as the bits work just fine and are probably more expensive if the label were to be placed correctly. Otherwise I'm happy with keeping this set for what I will use them for. Though "Wire guide number" bits will not be used too often for me, this set will be very useful in the future.

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