I have the hub that mounts to the tapered section,with a magnet in it for the electronic ignition I just need to make the part that holds the prop. does this thread directly onto the shaft? is it ok if the threads are aluminum? will they hold up OK?

then you use a bolt through the center (what size and thread?) to hold the prop on. or like the echo one BUCK1856 made with the small screws threaded into the end. Correct?