Cobalt Drill Bit Set (1/16-1/2 Inch, 17PCS), M35 High Speed Steel Twist Drill Bits for Stainless Steel, Hard Metal, Cast Iron, Plastic and Wood

Great quality at a great price

Ok

I'm not a professional mechanic or fabricator, but these are by far the best drill bits I have ever used. When drilling holes through steel they seem to be way sharper than what I have been used to and I usually use quite expensive drill bits. If and when these wear out I will purchase them again.

Each one was enough to drill about 20 holes in 3mm steel.

Bought these when i have to drill out locks for people that lose their keys. Worked in 1/2 the time as prev brand i was using so im calling that a big success

Bought for work. Sharp, nice quality, sturdy case, and nice selection of sizes.

Edit:The seller responded to me immediately and made it right. I do appreciate how swiftly the stepped up and that they did not give me any run around or hassle. I can honestly say Stroton does stand behind their products. For this reason, I updated the review to 3 stars. I still had a bad experience with the product but I had an excellent experience with the seller.Original review:Fist use, I drilled a 7/64 pilot hole into a head bolt that had snapped off in the block, I was happy with the performance of that bit, drilling and removing broken torque to yield head bolts was the reason I bought these bits. However, as soon as I stepped up to the 1/4 bit to drill the final size for the extractor I was using I ran into problems, the cutting edges of the bit snapped off the bit tip as soon as they grabbed, never even really dug in, just heard a crunch as soon as I started the drill. I've been welding, drilling and working with metal for decades, I've never had a bit break like this, where the tip just crumbled as soon as the bit started to grab. I was manually drilling, with an 18v drill, starting the drill slowly with very little pressure and using a cutting oil. The bit is still full length, the center point is intact, the sharpened cutting edges just broke off as thin flakes as soon as I started the drill. I wouldn't recommend these bits. I don't care what their warranty is, if you cannot use a bit, if they are that poor of a quality, do you really want to have to put jobs on hold waiting on replacements that might not be any better in quality? The set comes with two 1/4 inch bits, I didn't even bother to try the other one. I wouldn't trust it to be any better in quality. My guess is that the bit was overheated during their sharpening process, making the tip overly brittle so that the cutting edges just snapped away as soon as any cutting pressure was applied.I got these cobalt bits specifically for drilling into the harder metal of the broken torque to yield head bolts that broke on removal, leaving the threaded portion in the block. Now I'm out the cost of the bits and still have 5 broken bolts to remove. It's a nice case but it's full of bits I cannot trust. Don't waste your money.

So far these are working great. Used to to drill holes for rivets while replacing rocker panels. I broke 4 other bits before switching these and they worked really well. I did break 1 of the 1/8 after 8 holes so we'll see how good the warranty is.