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

This is by far, the very best and highest quality drill bit set I have ever owned. Unlike other bits I have encountered, these bits stay sharp and get the job done. They are ideal for drilling through steel and iron plates leaving sharp, clean holes every time. The warranty is also great - break a bit and they will replace it free of charge. Warranty card is inside drill box. While I'm praising the bits, let me also acknowledge that the drill bit storage box is really nice too. Yes, it's plastic, but the quality stands out from other brands as well. The bit clamps actually "hold" the bits tightly in place while stored, and the closure mechanism is top of the line too. I am NOT a paid reviewer or someone who got the product so I would review it. These are my actual assessments of this product. I just felt strongly enough about it to let others know what a great product it is and give STROTON their deserved credit.

Great set. Having two of the some of the small or more commonly used bits is much appreciated. Case is solid and holds the bits in place without making them difficult to remove.

These are so top grade. My grandson loved them and was bummed very excited.

Good and sharp. Cuts stainless like butter Drilled through 5/8 plate smoothly, nice ribbons. 2 step 1/8 and 1/4 holes. And remember always use that cutting oil and mind your speed, slow and steady gets them nice clean ribbons

Bits are holding up very well, good buy for the price.

Very good quality excellent case and nicely packed. Only used one bit so far. But they seem good quality

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.

These are good drill bits. So far I have drilled 8 half inch holes through 1/4” steel with it. It cuts good and has stayed sharp so far.