Since equilibrium must be satisfied, the $480-\mathrm{kN}$ force applied to the plate must be resisted by the shear force developed in the bolts. There are four bolts connecting plate $\left(1\right)$ to the splice plates, and each bolt develops shear stress on two surfaces (i.e., parallel to both the top and bottom surfaces of the steel plate). The shear force developed on each bolt surface is the product of the shear stress and the bolt cross-sectional area. Therefore, the equilibrium equation can be written in terms of the shear stress as:

$\sum _{}{\mathrm{F}}_{\mathrm{x}}=480 \mathrm{kN}-(4 \mathrm{bolts}) \left(\frac{2 \mathrm{surfaces}}{\mathrm{bolt}}\right){\mathrm{\tau A}}_{\mathrm{bolt}}=0$