EFFICERE 8-Piece Premium 1/2” Reduced Shank Silver and Deming Large Drill Bit Set in Aluminum Carry Case, M2 High Speed Steel, 135-Degree Split Point | SAE Inch Size 9/16” - 1” by 1/16th Increment

When I received the bits I was impressed by the quality. The case was a nice touch. I was looking for inexpensive bits in this general size range. I am working on a car that is really a resto-mod 1965 El Camino. I am fabricating a four link rear setup using factory mounting points. I didn't buy ready made trailing arms, but designed these to be fitted with larger grade 8 bolts. I hoped that the drill bits would last for the drilling operations for this project. I drilled several holes in various steel plates for tapping threads. I am impressed at the ease with which these bits cut through, leaving well finished surfaces to tap. After several uses, these bits seem to work like new and will not need replacing, or sharpening any time soon. I nearly spent three or four times more for "name brand" bits, but I am really glad that I didn't. I don't drill holes for a living or have to meet deadlines, so for me these seem like top drawer stuff! I appreciate the card that I found in this set of bits, seems like this is a company who is intending to make a splash in the metal working industry! Thank you so much for engineering quality into your tools!

Great set of bits. Needed reduced shank - large diameter bits - to use with my 1/2" hand drill. The bits I have used so far have cut well though 7/16" steel just fine. Take your time and use water based cutting fluid as you should with any drill bits of this size. Larger bits like this undergo lots of stress drilling large holes, especially through thicker material/metals. Use water based cutting fluid/lubrication, take your time, and the drill bits will serve you well. Great price and value!

If I could go back in time.. and do it all over again.. would I buy these drill bits in the first place? Well, of course I did! As a matter of fact, I bought 2 sets of them, which was really confusing because in the future, I ended up buying 2 sets of something that I didn't "yet" know that I already had! Needless to say.. you'd be had pressed to find a better set of HSS split-point drill bits for the money.. anywhere.. except for right here at this very spot, about.. ohh.. 3 days ago, when I found myself pressing the "add to cart" button for a product that had already been shipped, and was already sitting on the bench in front of me! (Don't ask, it's part of the time traveling machinist paradox). But that's niether here, nor there.. (Dad joke) But getting right down to the quality of these bits, and why you'll want to own a set (or 3) of these for your small home shop.. let's start with why other Amazon users will tell you you shouldn't. To speak to anyone who leaves a bad review of this product, you have unrealistic, and far-too-great expectations.. and hasn't your father ever taught you that, you get what you pay for, and you can't get something for nothing? Well, what you CAN get (for NEXT TO nothing), is a nice little set of fully-formed, HSS, split-point, drill bits! These bits DO serve a purpose, that purpose just doesn't happen to be "to replace the need to buy an expensive, heirloom quality, set of precision twist drills" For the amazing low cost of this product, you can expect to get a set of reasonably accurate, factory formed and sharpened, set of twist drills that will cut reasonable well in softer metals. These bits WILL displace some chips, and will leave a reasonably formed, somewhat smooth, hole in soft metals like aluminum, brass, bronze, softer steels like free-machining steel (use cutting oil) etc. I WOULD recommend going through the set with a fine hoan, or possibly a set of progressively finer oil stones to knock down the harsh "Burr" that was left behind by the extremely high-speed production process used in the Chinese factory where these are made. Once you "go-over" the flutes and the split points and spend a little time dressing them up a bit, they are actually REALLY nice bits! ..with one caveat.. So long as you USE them in a REASONABLE manner, and don't expect them to chew precision holes through hardened tool steel with ease and purpose! They aren't made for this, nor do they promise this! These aren't the set of bits you'll find at a swap meet in 40 years, selling for $100 or more, because they aren't the type of tools that were hand ground from the finest steel, with the strictest accuracy and highest level of precision by an experienced artisan. They're inexpensive hole-makers, meant to bore holes in softer metals when you either don't care about how accurate the final hole is.. OR.. if you're like me.. they're meant to be mounted into a tailstock lathe chuck, where they will slowly core their way through chunks of aluminum, and the holes they make will almost always be "finished" by me using a boring bar/hoan, which will bring the slightly "mucky" hole made by these bits up to a precision hole with a smooth, mirror-like finish. The reason I enjoy using these bits, and why I say that they DO have a place in.. even high-end machine shops, is because they DO what it says on the tin.. after a little clean up, so long as you take your time, use a slow rotation speed, add plenty of coolant/lubricant, stop occasionally to clear your chips (peck drill), then these bits will remove a ton of material in a fairly short amount of time. If you don't think you should have to clean up each bit by hand, right out of the box.. then, I don't know WHAT you thought you were getting for the price you're paying for these bits, because I feel like I should have paid the asking price just to SHIP this much steel all the way from China, and if I were to buy a comparable quality set of bits at ANY local retail outlet, I know that I'd be looking at paying between 2x to 3x as much, and even at that price, id likely STILL have to touch them up by hand before using them, if I wanted them to cut at all and not just spin around, squealing, and making smoke.. or having one of the flutes catch a Burr on my workpiece and damn-near twist it out of the vise. So, having to do some work with the hand stone was something I FULLY expected when buying these at this price.. which is FINE with me, because i appreciate paying so much less for a simple set of HSS split point bits. At least now I won't feel bad if/when I eventually break, bend, or lose one.. or when my neighbor inevitably asks me, "hey, you mind If I borrow a 15/16" drill bit" -- This way I can hand him one of these, knowing FULL well that I'm going to have to run it up against the bench grinder when I get it back, JUST to try to get SOME sort of factory shape back into it, because as you can imagine, it's a LOT easier to just lend him something cheap, knowing he'll break it.. than it is to have to try to explain to a non-machinist why he can't use one of your "good" drill bits which cost $20-$50 EACH, for him to try to chew a hole through his trailer hitch receiver, at 1000 RPM with his cordless drill, wondering why it seems to have just "stopped cutting", as he continues to WOLLOW the tip around inside of the smoking "divit" he just created, watching the bit turn from a beautiful steel-blu, to shades of yellow, pink, purple, and ACTUAL blue. The sequel that's coming off of the tip of the borrowed bit is actually the tool itself, screaming in agony, for him to STOP.. but he won't, he will continue to push even harder, tilting his drill around in a circular motion, making sure to adequately burn off every square mm of potential cutting edge.. before he finally stops, to proclaim, "Man, this drill bit is a POS" at which point he will hopefully give up, and bring you your drill bit back, telling you "it worked great! Thanks again", and you can take you abused twist drill back over to the bench grinder and spend a little time bringing it back from the dead. But.. if he's like MY neighbor, he'll stop and say, "geeze, your drill bit was really dull, and my uncle told me one time that a dull drill bit is a dangerous one, so.. I watched a couple of YouTube videos and I sharpened it up for you!" Either way, you don't want to borrow an expensive drill bit to your neighbor, and you don't want to try to use inexpensive drill bits to bore precision holes through hardened steel. For both scenarios, you'll want to find a nice, inexpensive set of, mass produced, HSS, split point twist drills.. and THATS what youre getting when you buy a set of these. And much like anything that is INSANELY inexpensive, expect them to be a little "rough" around the edges, and expect them to need a little TLC, in the form of a little bit of hand sharpening/touch-up before you use them (small price to pay for such great savings).. And finally, expect to go a little slower, use a little lubrication, and only drill into softer metals.. and if you DO.. then you will end up loving these bit for a very long time! Thanks for watchin! -This 'not young' Tony

I've learned that these work better on low speed than high speed. I'm using them in a drill for a wood and aluminum arbor press upgrade project. If you press on the top of the drill with your hand weight and use low speed it cuts bigger chunks. High speed works but takes longer. Always drill a pilot hole. It will make your life much easier as shavings fall through the hole instead of the bit churning on them. I found stepping up in bit sizes progressively didn't produce as nice result as a single pilot hole and then final bit size. Still sharp after drilling through 3/4" 6061 aluminum plate. This is a good quality bit set and will fit in most battery power drill chucks.

Worth every penny. I used many O drill bits in my life. If used properly, these will work very well. Hole sizes will be oversize but you'll get that with pretty much any drill. If you want an accurate hole, drill undersized and use a reamer or boring bar. I just received these and tried a couple out in my mill (with pilot holes) and they make chips very nicely. Most definitely will order again if need be. I may purchase the metric set just to liven things up in my little shop a bit. I have 18 years experience as a machinist in a heavy machine shop. Buy them, you won't regret it.

Buen producto👌 es la segunda vez que compró estás brocas y para el precio funcionan correctamente. Lo recomiendo ⭐⭐⭐⭐⭐

pour mon utilisation c'est parfait

Entrega muy en tiempo, presentación tal cual su fotografía.

USED ONE BIT SO FAR WORKED GOOD. I THINK THEY WILL WORK WELL!!!

The reason for only 4 stars is I haven't used them much yet. I had no problem drilling a1" hole with a 3/16 pilot hole in 3/4" mild steel flat bar at around 200 RPM using lots of cutting oil. For my occasional use only needs which doesn't warrant spending $100's of dollars more for a professional grade set I am sure they will be just fine. Just make sure your drill press has the capacity and slow speeds required to handle the larger sized bits.