For the injector faceplate to stay fastened to the manifold, the bolts must satisfy a factor of safety for both tensile and shear stress. A net upward pressure acting on the faceplate applied to the area of the injector requires all bolts on the injector manifold -both axial and radial- to withstand this force to maintain structural integrity.

Hot Fire Calculations:

F_{up} = P_{injector}*A_{injector} \\
F_{up} + N*F_{bolt}=0 \\
|F_{bolt}|= \\

Desmos: https://www.desmos.com/calculator/erjdwzmlve