Buddha Jones said:Giving away some trade secrets eh ER?
I don't exactly consider this as the trade secret though I do know that only a handful of us do this. Most, as Joseph Cues mentioned, just use unthreaded wood tenon and a Metal 3/8x10 or 16 bolt. Plus the pictured isn't really "the" trade secret of my forearm/handle joint but something more mind boggling.
Are you also a cuemaker?