Introduction: Drilling and Tapping Hardwoods

About: I'm a retired mechanical engineer, woodworker, boater, and inventor. Now I'm getting into wood turning, and have found that all my wood projects need not be flat and square.
Drilling and tapping hardwoods
 
There are several ways to attach threaded metal fasteners into wood fixtures. For example,  inserts and  t-nuts can be used to add  a threaded connection to a jig. But often I prefer to drill and tap threads directly into the wood fixture.  Many hardwoods can be drilled and tapped, however softwoods lack the necessary machinability and holding capacity. The best wood I have used for threading is Jatoba,  (Brazilian Cherry). Jatoba is very dense, hard, fine grained, and threads extremely well. Oak and Padauk are fine also. I find these threaded wood fixtures hold a bolt extremely well.
 
Hardwood is a forgiving material to drill and tap. Use a 5/16” drill bit for 3/8” threads, 7/32”  bit for 1/4 “.  I don’t thread anything less than 1/2”  thickness. Use a standard coarse tap to cut the screw threads. 
 
Making threaded woodworking jigs, clamps, furniture handles and knobs from exotic hardwoods adds a beautiful touch to projects.  Material is not cheap, but these parts are small so final cost is low.