screws versus nails

huangyhg

screws versus nails
i need to attach a wood rail to a post for a fence.  someone suggested using a kreg pocket hole jig that uses screws.  do screws have more or less shear strength than nails?  does anyone recommend using screws over nails or vice-versa?
shear strength will vary with the diameter of the fastener more than with the strength of the metal; the shear joint will usually fail when the wood under the fastener compresses.
what a screw will provide is withdrawal resistance for a longer time if the fence is exposed to the weather. if you want to make the fence more than decorative, i would recommend screws, rather than a nail. i can tell from personal experience that a worn 6d nail in a fence is weaker in withdrawal than a lab retreiver puppy...
do i know you trussdoc?  how did you know that i am making the fence b/c of our new lab retriever puppy???
just coincidence....i was just amazed how much damage an excited dog can do, and how weak nails really are in withdrawal.