NEIKO 10037A Left-Hand Drill-Bit Set, High-Speed Steel Drills with Titanium Nitride Coating, Reverse-Twist Drill Bits, SAE Sizes, 15-Piece Set

This worked like magic. I was skeptical at first and even after I drilled through the remains of the snapped bolt. I took my time to slowly drill through the bolt with a smaller bit. After I got through, I switched over to the next size up. It started to drill slowly then eventually got caught. Once it got caught, I started to drill in slow bursts which eventually freed the bolt from the engine block. It quickly unbolted after that.

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.

May break easily at high speed when drilling out broken screws. Slow down and use a lubricant.

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.

Works good, no problems.

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.

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!

have yet to try out these bits to see the durability of them, but upon arrival of the bits the case does not stay closed the rack that holds the 5/16th - 1/2 bits will not stay put in the (it appears that the rivets that hold it in are missing) I would compare it to harbor freight quality but a little higher priced (might be comparable if HF had the same sizes) and at least I could return to the store if I had an issue. if these were standard bit I wouldn't care so much for the case, but with these being left hand bits I want to keep them separate from all my other bits. EDIT: got around to using these bit and they worked well for the first drilling second I stopped and started to drill again they did not seem sharp anymore and took alot of pressure to make any sort of progress. ended up going back to my old colbalt bits and gave up on trying to extract the bolt

Très satisfait de ce lot de 13 forets gauchers NEIKO. Le coffret est bien présenté avec plusieurs diamètres, ce qui permet de choisir facilement le foret adapté au travail à réaliser. Je les ai trouvés particulièrement pratiques pour travailler sur des vis ou boulons endommagés et pour différents travaux de mécanique. Les forets coupent correctement, accrochent bien le métal et donnent une bonne impression de solidité lorsqu’ils sont utilisés correctement. Le rangement est également un vrai plus : chaque foret reste bien à sa place et le coffret est compact, donc facile à conserver dans une caisse à outils. Un ensemble très utile pour le bricolage et la mécanique, avec un bon choix de tailles. Très bon rapport qualité-prix, je recommande

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.