Bit and tap worked great. My only complaint is that the tap is an awkward shank size and doesn't fit in a small tap holder, and was a little awkward to use in a large tap holder. I was able to get it working by plugging the shaft into a cheap 10mm socket and using a socket wrench to do the job. My big issue with this kit is the coiled coils. The shaft won't break no matter what I do. I actually messed up a helix trying to break the stem. I tried the tool that came with it and a pair of needle nose pliers. Nothing worked! For the price I think it's good value for money. And since I don't use a frequency coil, I can't completely rule out an operating error with a broken shaft. But in the end he got the job done and I was able to fix the stripped drain plug threads on my car, giving it an 'Average' rating.