Nails cannot reliably resist tension, but are used where shearing forces dominate. Screws resist both shear and tension, up to the limit the material will tolerate before failure.
If joined materials must resist being pulled apart, use screws. If the joined materials must only resist sliding across each other, use nails.
Wall studs need to resist compression loads. Their ends need only be secured against sliding out of place. Thus, it makes sense to secure studs with nails.
Latest Answers