I machine dadoes in ¾", ¼" deep. If it's a good fit, just use glue and clamp it up. No pocket screws.I'm building a bookcase from poplar (grandson wants to paint it, so why use the best wood). Anyway, I Have a 3/4 thick side panel with a 3/8 deep x 3/4 dado cut in it for a shelf. I plan to glue, but don't want to screw thru the side panel. Can a pocket screw hold solid on underside of shelf--thru the dado and shelf...and if so, what length should I use?