NEIKO 10038A Left-Hand Drill-Bit Set, High-Speed Steel Drills with Titanium Nitride Coating, Reverse-Twist Drill Bits, SAE Sizes, 13-Piece Set

Had a cleaning rod in which the brass screw-in jag broke off. So I ordered this set. Dimpled the center of the broken stud with a center punch and using a bit that was smaller than the diameter of the broken stud, proceeded to drill into the stud. Within 15 seconds it backed itself out and my problem was solved. This set came in handy and I'm sure I'll need it again for similar fixes. Nice little set at an economical price.

I was installing new titanium axle punch bolts on my surron dirt bike, and I gave one of the bolts one too many ugga duggas and it decided to snap, leaving most of the bolts threads in my fork leg! That's a crazy expensive and difficult repair/replacement I definitely couldn't do myself, so I researched and found this kit. It had a small enough size bit for the tiny bolt, since my extractor kit I already had only had ones too big. Now this is a bolt made of Grade 5 titanium, so really strong and defiant to everything. I started at the smallest size, drilled for about 15 minutes to make a pilot hole (not the tools fault, again this is titanium), then moved up another size, made the hole bigger. Finally I moved up one more size, and almost immediately it caught and the rest of the bolt came out! I was not expecting it to work, but it did. Saved me a few hundred bucks replacing a fork lower leg 😁. Would recommend! In the attached image, the blue bolt on the left is how it's supposed to be, the right one snapped off. The other picture the rear part that this kit helped me get out!

Be careful opening the case. The lid was so tight, when it finally gave way, the bits went flying everywhere. The quality of the bits seemed fair enough, but I broke the first one I used trying to extract a busted bolt on a hot agitator. The steel bolt had become hardened from excessive heat and the bit wasn’t even making a mark before it snapped. I ended up replacing the whole part. I grabbed a piece of 1/4 inch steel stock and drilled a couple holes through it without any trouble just to see if the bits could do it. Take your time and use cutting oil when drilling on metals.

I do most of my auto repair by myself––age 73, so no novice, but not a pro by any means. I had broken off two of the five valve cover bolts on my '02 Honda Accord while tightening down. (Watched too many videos on the subject and tried to use my 1/2-inch torque wrench, which just wasn't made for a light 7 foot-lb. setting. Next time, it's back to the old "feel" method.) These are 6 mm (just under 1/4-inch) bolts that have a flange on them that prevents tightening them down too deep into the aluminum head. So I suspected they were not jammed into the threads. They should come out easy if I could get a drill into the bolt center and reverse thread out. I tried my set of Grabit brand easy-outs, but it just made a mess of things. You set your drill on reverse and use one end to drill a pilot hole (they call it "burnishing"). Then you flip the bit over and use the other, reverse-threaded end to try to grab the bolt and screw it out. I tried the #1 and #2 Grabit bits, but no go. I suspect these are only good for soft metal, because I spent nearly an hour drilling and very little metal was removed. They just left a rounded depression in the top of the broken bolt. Their promotional videos always show it being used on wood screws, which are softer than automotive bolts. I switched to a nice set of titanium drill bits that I reserve for metal, no wood--trying 7/64, 1/8, 9/64, 5/32, and 11/64. Nothing would remove much steel. I haven't used this set much at all, so could not believe that every bit was dull. I began to suspect the bolts were made of a hardened steel, and might require carbide bits. Called a mechanic friend who told me he wouldn't do it, but knew a shop that could weld on a small nut and take it out. (Visions of big bucks began dancing in my head.) But he also said his brother had just used reverse drill bits to solve a problem on his motor cycle. Figured I'd give it a try, and almost drove down the local AutoZone to buy their set of 5 reverse bits for $9.99. Then saw that Amazon had this set of 13 reverse bits for only 3 bucks more, and I've had good luck with some Neiko products. So I waited the two days for Prime delivery, and so glad I did. Right away, I noticed the Neiko 1/8" reverse bit was really removing some metal. I had to also try 9/64 and 5/32 before it grabbed into the chewed up bolt head, and easily turned it out. The second bolt which I hadn't bolloxed up with a Grabit and other drill bits, just wound right out on the first try. Boy was I happy. Problem solved. This method should work for the rare bolt that has broken off this way, not because the thread is frozen or welded in there like you find on exhaust manifolds and other places--that's a whole other story. But for a small bolt that broke off the way mine did, I swear by this product.

If you've ever broken off a bolt below the surface, you know what your choices are: Try to tap it out with a punch, drill it out, use a bolt extractor, weld a nut onto it, etc. One that often gets overlooked is using a left hand drill bit. Since most bolts are right-hand thread, drilling with a left-hand bit does two things at once: It weakens the bolt which reduces the pressure on the outside holding it in place, and it provides a twisting force in the direction that unscrews the bolt. Often this is enough to get the bolt out by itself. If not, you either keep drilling or you use a screw extractor in the hole you just created. Very rarely do I have to go any further. This set of bits will handle small and medium-sized bolts and screws, and it does so well. The bits themselves have a tendency to get dull but they're not difficult to resharpen. Since I only drag them out when I break a bolt, they don't get a lot of use and thus last a long time. Would they survive in a machine shop? Maybe not. The metal is fairly soft and it doesn't take much to chowder up the cutting lips. But they've been in my home shop for 10 years and are still going strong. I use them sparingly, but when I need them they usually solve the problem quickly.

For $26 you get what you pay for. Yes, they do cut. However, it doesn’t hold an edge and they don’t last long. Even utilizing quality cutting oil, sustainable and careful pressure, I snapped two of the smaller bits. Not strong material as advertised..!! For $26, not much of a loss. However, save your money and pay for higher quality drill bits if you want them to last. I will be spending the money for quality next time. Expected more quality from these bits. You really need to do your homework these days and buy quality.

These bits and a good center punch help when removing broken bolts.

Not magnificent. Cheap lefthand drillbit? Yep. Effective? Not very. Broke at least 1 bit. Typical chinese stuff, not for particularly tough jobs, the price says it all.

Buena calidad de materiales y muy bien el estuche, bueno filo para cortar materiales duros, tuve que usarlas para sacar un prisionero de cabeza Allen barrido y funcionó muy bien. Hay que darle el tiempo que necesita para cortar.

buena compra

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I broke the antenna off my truck in a carwash, and I needed to extract the broken threaded part left inside the base of the unit. Drilling a hole with a regular drill bit would only drive it down further. I looked up a left hand drill bit set on AMAZON and found and ordered this item. After receiving the left handed drill bits, I selected the drill bit a bit smaller than the broken shaft left inside the base. Within seconds of using it the broken shaft reversed upward and I was able to remove the broken piece and then replaced it with a new antenna. Thanks.

They do the job I wanted them for.