Tools IRWIN Drill Bit Set, Cobalt Alloy Steel, 15-Piece (316015)

So much better than the less expensive bits I’ve always purchased.

The only type of bit to use for Stainless and use it on a VERY low speed with plenty of cutting fluid. Never use a hammer mode with these. Treat them well and you'll only rarely need to sharpen them.

Good quality product.

used with some truetap cutting fluid and a Milwaukee d-handle drill from the 60s to drill multiple 5/16, 3/8" holes in 3/8" steel plate and slightly thinner angle for mounting a winch to an F250. These were great, I will never use anything but cobalt, and these Irwin were awesome for the money. I wished it would have come with a 1/2" bit but other than that, super solid buy.

Fantastic, opened it up and progressively drilled up to 1/8" to extract a sheared bolt with no issues. Be sure to use some kind of lubricating oil like CLP or Seafoam DeepCreep to keep the cutting edge happy and stop periodically to blow out your chips. Also, using a center punch to get started is a must. I'm glad that I got this drill set and I'd recommend it.

I had to enlarge a hole into hardened steel and every other drill bit I had wouldn't even scratch it. These drill bits made the hole that I needed. Granted I had to stop occasionally to allow the drill, bit, and metal to cool back down, but it eventually went through. Highly impressed. I will be looking at more cutting tools with Cobalt infused metal.

Did the job very well. Sharp, cut well, just a drop of cutting oil and went slow so as not to overheat. Broke three high speed steel drills on the same job.

Sturdy case. Drills seem sharp and hard enough not to dull on soft metal drilling. I like the multiple pieces of the smaller -- more easily breakable -- drill bits. I dinged one star for the expense.

Después de algún Par de años de usar siguen funcionando muy bien, el producto a conservado filó el material es muy bueno

I've owned many high drill bits, Way more expensive bits than these. After drilling two holes in the same thickness steel I've had to sharpen them to make a third hole. These IRWIN bits...One drill bit drilled 8 holes like a hot knife going through butter. I always use oil. I've used the same bit to drill another 16 holes with oil and it still is sharp enough to drill more!

Me ha servido para taladrar metal, concreto y plástico, no sé si el uso sea el adecuado sin embargo hacen un excelente trabajo sin verse afectadas.

Great set, now drill through steel and metal with relative ease!

Good quality