The instructions call out 5/32" holes when using the provided screws. You would use a 3/6" bit to enlarge the hole in the wing leg. For any other screw size or pin dimension, the basic concept is a net fit through the deck and crossbar. You want a little looser fit in the wing leg, so you oversize that hole so the pin or screw is just a sort of keeper pin. Not a tight fit. Allows the seatback to flex in an out a little without working directly against the tip of the pin or screw.


Seat installation instructions