IRWIN Drill Bit Set, M35 Cobalt Alloy Steel Steel, 29-Piece (3018002)

i use these all the time they hold up well , i have bought several through the years and always good quality they work perfect on hard steel ,i would never buy cheap bits again ,well worth the money

Highly recommend for hardened steel

I make no pretense to being a professional machinist, et cetera. In truth, pre-MBA, I was a scientist via mathematics. So, if your metric for relevance is related-professional-experience, give my review a skip. Indeed, I spent four years at a posh, New England prep-school, so, I even missed learning experiences such as "shop classes," ... among other things.Prior to these Irwin cobalt bits, I was of the, "crank up the (rotational) speed and hope for the best," school of metal drilling. Stupid. Watching (literally) these bits work provided a priceless, hands-on lesson in applied physics and physical metallurgy. Slow the rotational speed down (W-A-Y down), judiciously increase pressure (id est, PSI-loading), and watch ever longer spirals emanate from your successive drillings. Conversely, crank up the rotational speed, cook the bits, and complain about poor Chinese product molecular composition, drill bit fabrication, or, for something utterly inane, the packaging. I "cooked" the Irwin cobalt 1/4-inch bit and split the 3/8-inch. Fortunately, those two were the extent of my tuition costs.Despite the "handicaps" enumerated in the first paragraph, over the last twenty-five years, I have built eighteen proper -- with foundations and electrified (as in, "electrons," thank you) -- buildings, worked on heavy equipment (through 40-ton 'dozer), and burnt "miles" of welds. So, while I'm not "professionally" credentialed in the machining/building trades, I had been sought out to "fix" mechanical/"mechanical" problems of many folk who were. I was far from an utter rookie when the Irwin cobalts arrived; I am sure glad that they did. I'll buy more if and as needed.

Great set and these drill bits are the best I've used (baring specialty bits that are as much as this whole set). We were recently drilling through some thick metal to attach some new wooden slats to a cart and I was using one of these bits to drill with. After about 40 holes (with no cutting oil mind you) and not taking much of a break between, I did finally break one. We needed to drill roughly 50 holes. Went to the hardware store and they didn't have any of these in stock, just the lower grade ones. Titanium or something, I don't' remember. Anyway, broke 5 bits in the last 10 holes. Basically, these are way better than the alternatives.The reason for 4 stars it that the case is kind of terrible. The smallest drill bit constantly falls out and the whole thing is soooooo chintzy. It has that feel like the execs were sitting around and said "How can we make it SEEM like it's high quality and still make it as cheap as possible?"Barring the lousy case, you'd be hard pressed to find a better set of bits for this low a price. I can't recommend it enough.

The bits are very good, very sharp. The case is terrible. Hard to open, hard to close. The top does not match the bottom. I would buy again only for the bits. I am looking for a good case. This one should be replaced by a good one. Someone in quality control is not doing their job.

Works great

Drill bits have always been like fingernail clippers for me....no matter how many I buy, I can never find one when I need it. I got tired of buying cheap, "throw away" drill bit sets that made more frustration than holes. I figured it was time to buy a nice set of drill bits so I picked up this Irwin set.This is a very nice cobalt set with a large assortment of sizes. Sure, you're paying a premium for them, but if you use them as intended, they'll last you years in a DIY environment. I've had mine almost 5 years and haven't broken a single one.I'm not a professional machinist, but I know enough to realize that even though these are "High-speed" drill bits, that doesn't mean you go full throttle when drilling holes. Take your time, slow down the RPMs, use a little bit of cutting oil and these babies will cut through anything and you'll still have a nice, sharp bit when you're done.Very impressed with this set and I would buy again.

Over 40 years I have purchased approx. 15 sets of drill bits for my husband. I finally decided that the old saying "You get what you pay for" rings true regarding this drill bit set. My son-in-law purchased a Dewalt 1/2 " drive (heavy duty) drill for my husband for Christmas. Using both products together really got the job done. He has used the bits to drill through 2 1/2 inch pipe to create a"portable" corral/loading area for out cattle. These products drilled through the thick steel materials like butter. He also drilled a hole through 1/2 swedish (hardened) steel with no "wandering of the bit" when starting the hole, it cut the normal time by about 75% (he would normally go through 2 or 3 bits that would dull or break before it would get the job done)total frustration!. This is an excellent investment that you should happily purchase as a very generous gift for the man in your life. It's always nice to see your husband happy the gift you have purchased for him, not like shirts or ties, a real investment in making his work easier for him.A "Ranchers Wife"