References for increased values for clinched nails

[mjohan]

I have heard of increasing allowable values for nails when the backs are clinched. The most common application I can think of is for wooden roof truss repairs. Can someone direct me to any literature or design guides which implement, and validate, the increased load capacity for common nails.

Thank you,
Mark

 

[johnplctech]

There will not be any increase in shear strength as you have not increased the diameter of the nail. There will be a small increase in the withdrawl index but only to the limit of the head diameter unless the nails are driven through a metal backing then the point cinchec over.

Look up National Wooden Pallet & Container Association and Virginia Tech they both have done alot of work on the withdrawal index of nails from oak.