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.Desmos: https://www.desmos.com/calculator/erjdwzmlve
The area of the bolt can be determined by using its pitch diameter, which is calculated using its major diameter and the spacing between each thread:
Tensile Stress on Each Axial Bolt During Hot Fire:
Shear Stress on Each Radial Bolt During Hot Fire and Approximation of Shear Strength:
Factor of Safety for Tensile Stress and Shear Stress During Hot Fire:Link to Desmos Calculator