On Friday, July 8, 2011 6:30:51 AM UTC-7, Jack Stein wrote:
On 7/7/2011 1:04 PM, -MIKE- wrote:

ASAIK, the heat treating done to drywall screws makes them resistant to
stripping out at the heads and resistant to breaking from the friction
of being driven by powered drivers. The treatment also makes them very
brittle and not good for resisting heavy shear loads

Classic wood screws for furniture, on the other hand, have a cylindrical
barrel that has good shear strength, are made of softer metal that isn't
brittle, and (best practice) are put into carefully predrilled holes. Also, they're
getting hard to find. That kind of screw, unlike drywall screws, never
competed with nails on price.