I’ve always heard about using left hand bits to remove broken bolts but have never tried them. I happened to see a set at harbor freight and they were cheap enough that I figured I’d try a set. I got home and decided to try them on a broken bolt in my cub hood. I started with a small one and started working up through the different sizes. As I got to the largest I thought I could use the bit grabbed in the bolt and spun it out. I was surprised at how sharp the bits were. They drilled better than some name brand drill bits in my collection do. I don’t know if I just got lucky or if all of harbor freights left hand bits are this good but for the price of the set I would recommend giving them a try