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

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

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.

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.

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.

These are the best drill bits I have ever owned. I'm no professional, but I do my share of repairs and DIY projects and I will never buy any other type of bit. Last winter a couple of bolts where sheared off on my snowblower (not the shear pins) and left the threaded portion of the hardened steel bolt inside without the heads. After trying an easy out (which never works for me) I decided to drill them out and these bits (which were far from new at the time) did the job. "Big deal" you might think, but I challenge you to drill through a grade 8 hardened steel bolt with anything else!

I bought these by mistake and had to return them but I noticed that they feel more solid than my Dewalt drill bits. When I need new bits, I’ll buy this set.

WELL I HESITATED ON BUYING THESE DRILL BITS BUT THEY DID HAVE GOOD REVIEWS AND IM GLAD I DID AS I HAD TO DRILL OUT BROKEN EXHAUST BOLTS & STUDS IN MY 1994 FORD RANGER WITH OVER 420,000 MILES THE ONLY THING I HAD TO DO IS PUT A AIR LIMITER ON MY AIR DRILL THEN JUST KEEP ADDING THE CUTTING OIL I BOUGHT WITH THE BITS ALL AND ALL IT DID THE JOB THAT I NEEDED TO GET DONE

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

Good quality

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!