MABLEVI 11 Pieces Screw Extractor Set, Metric Easy Out Bolt Extractor Set, Reverse Drill Bit Extractor Set for Removing Broken Screws, Bolts, and Studs

All the left-hand / reverse drill bits and the extractors are very well made. The markings for their size is kind of faint on these bits, but the case is made such that each bit fits in only one slot, easy to tell which is which by the markings of the bit size inside the case for each slot. Excellent case, by the way: keeps everything organized and the slots do retain well the bits.There is no substitute for actual usage in getting a real sense of the quality of such extractors, and so far I did not have an occasion to put this extractor set at good use. Over the years I had my fair share of shattered extractors, after all these come into play when things are dire, a bolt that has broken inside a hole exactly because it was stuck to begin with. The chances of extracting the stuck part of the bolt while saving the thread on the hole are pretty low. I don’t need both hands to count on my fingers how many times this actually worked for me with other extractors. This extractor set, by design, maximizes the contact surface to the broken part and provides for drilling in reverse to the normal threads, avoiding furthering the broken bolt inside the hole. All chances are this will work better where other extractors did not. If I will find they do not, I’ll let you know here in an update, later.

I hate breaking off screws and bolts when trying to remove them. If all you've got are conventional tools, all you can do is try to drill them out, and when your goal is to preserve the hole and threads, it's often futile. You probably won't be able to drill the remaining part dead center, and you're likely to destroy the threads of the socket you're working on.Screw extractors really only work if they have something to grip. This kit includes 5 different size reverse-drill bits, and 5 broken-screw extractors. They're hardened steel with a cobalt coating to keep the drills sharp, and are designed with hex ends for quick insert and change. A quick change adapter is included, and everything fits nicely in a sturdy blow-molded box.Once I centertapped the broken bolt, the reverse bit went through pretty easily, and the broken-screw extractor bit right into it. I used a tap wrench as recommended, but you can use your power driver on a very low speed to take the broken screw out without damaging the socket.

This set of left had twist drill bits and extractors have already saved the day for me. Had 2 rusted and broken bolts. 1 came out with just the LH drill bit, the second needed the extractor. 100% success rate.