Combined Shear and Tension 
 ASD
    Q / (2.7 t₁.d.F_u1) + 0.71 T / (1.5 t₁.d_w.F_u1) <= 1.1/O     Eq. E4.5.1-1
 LRFD
    V_u / (2.7 t₁.d.F_u1) + 0.71 T_u / (1.5 t₁.d_w.F_u1) <= 1.1f     Eq. E4.5.2-1

     t₁ - thickness of member in contact with screw head or washer
     d_w - larger of screw head diameter or washer diameter
     F_u1 - tensile strength of member in contact with screw head or washer

       O = 2.35
     Q - required allowable shear strength
     T - required allowable tension strength

      f_v = 0.65
     V_u - required shear strength
     T_u - required tension strength

  Minimum edge Distance
    e >= 1.5 d

  Minimum spacing of screws
    s >= 3 d