screw just isn’t appropriate, maybe a machine screw would be. The WOODWHISPERER has introduced a set of taps made for tapping wood for machine screws. They appear to be significantly longer than the taps usually found for metal tapping. Here is a URL that will show a method for making your own taps for machine screw applications in wood.
http://www.instructables.com/id/Make-a- ... dium=emailI have found that some ca glue in the tapped hole , when cured, gives me just a tad more confidence that the threads will hold when the screw or bolt is inserted. Tapped holes in wood really do hold well and make jigs much easier to assemble and adjust.