Nice durable bit cuts very well seems to last a long time cobalt is definitely the way to go it’s night and day compared to the other drill bitsGreat drill bits good price quick shippingHave you ever gotten frustrated breaking bits trying to drill steel? Throw a drop of cutting oil on the tip of one of these and cry no longer. They're worth every penny. The only mystery is... why a THIRTEEN pack? Somebody was having some fun with that one. Still, great bits, last a lot longer than typical Titanium Nitride or HSS bits, and come in a nice little plastic carrier.Exceeds my expectations on metal. Highly recommend.The drill bits are holding up well. They seem reasonably sharp. They are small diameter so I break them, but if there is enough left I sharpen the broken bit. They still cut, but not as good as the original bit.My project required drilling thru thin 1/32" stainless steel sensor probes. After ruining several standard high speed 1/16" drill bits, I decided to try these.The pros:+ Pretty good price of $7.99 for 16 bits with free & fast Amazon shipping!+ Advertised - 13 pack of Cobalt drill bits.+ Advertised - M35, fully ground, 135° split point, bits contain 5% Cobalt.+ Advertised - Plastic storage case included.+ Advertised - Cobalt drill bits are the perfect drill bit for hard materials such as Stainless Steel, Hardened Steel, Cast Iron, Bronze, Titanium, and More!+ Advertised - LIFETIME GUARANTEEThe cons:- Made in China, for those that prefer to buy products made in the USA.Closing remarks:▪ I drilled 3 holes in 1/32 stainless steel with no issues, using CRC 3-36 as the cutting oil.▪ Even with the pressure I placed on the drill bit, it didn't break, VERY impressive!▪ Once I drilled the 1/16" pilot hole, I was able to use my standard #43 high speed drill bits to enlarge the hole for tapping threads for 4-40 machine screws.▪ I'm still on the first 1/16" drill bit! VERY impressive!Good eThey were alright