The 'nut' in the photo is just a hole with threads tapped in the wood. It is a perfectly fine setup for bolting on a wing. Like Minn and Minn said, after tapping the threads, drip in thin CA and wait until it is completely cured. Do not spray it with accelerator. After it cures, i like to run the tap through it again to clean up the threads.

Blind nuts are another option, but I don't like them as much.