I bought these a couple of years back off the web for pennies. Used them.the first time today to clean up and repair the thread on an 8mn dia main ground cable bolt.
Space was very restricted so used with a 1/4"drive ratchet with square to hex adaptor.
Good tool saved a lot of time
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)