I used this on a tap that was to large and broke it, however it was not the products fault, I used it on to large a tap. These are available in a number of sizes so make sure you have the right size. They also come in 4,5 and possibly 6 flute. This was the only product that would grip the broken off tap which was way to hard to use a reverse drill type remover. I would recommend this product to anyone I had a 10-24N tap which is around 3/16 had it been an 1/8th inch tap it would of worked great. A Tap is high tempered steel unlike a screw which would have came out easier as well.