Tutorial that show seven techniques to extract a broken screw

Com :Stefan: seems everyone forgot about using a left handed drill bit.  you don't use the drill bit to make a hole you want it to grab the bolt and back it out. if you know how to sharpen bits by hand change the angle to 140 degree or flatter. if rusted use a good penetrating oil and don't rush the soak. use caution and safety glasses when trying any of these methods...