Rivets and bolts subjected to both shear stress $$\left( {{\tau _{vf}},\,cal} \right)$$ and axial tensile stress $$\left( {{\sigma _{tf,cal}}} \right)$$ shall be so proportioned that the stresses do not exceed the respective allowable stresses $${\tau _{vf,}}$$ and $${{\sigma _{tf,}}}$$ and the value of $$\left( {{{{\tau _{vf.cal}}} \over {{\tau _{vf}}}} + {{{\sigma _{tf,cal}}} \over {{\sigma _{tf}}}}} \right)$$ does not exceed