How do you install a hanger bolt into wood,without messing up
The threaded that will take a nut? See picture

Put two nuts on the end... tighten then against each other and they will lock tight enough the outermost nut can then be used with a wrench to thread it in... and the nuts come off just as easy after its in.

I use Smoothy's method or run an acorn nut over the thread. Easier to screw down since you don't have to align the flats.

Very good