how does one determine the number of pounds of pull required to separate two nailed or screwed boards? or how does one know if the nail or screw you are using will hold up with with separating pressure? There are so many types of nails and screws. How does one know which is best for a situation?
Also, I want to screw a 2X6 inch board through a gypsum wallboard, into two metal studs which need to resist a 80 lb pull. What kind of screw or bolt, what length need to be in the metal stud and what diameter is needed?