On most, no, little to no braking force is taken up by the fasteners themselves. For most designs the calipers sit inside a frame that takes the braking force, and the fasteners simply hold the caliper in alignment within that frame.

This wikipedia photo happens to be from an AMC pacer, but it does show the frame that takes the braking torque load (https://en.wikipedia.org/wiki/File:Detail_of_-_AMC_Pacer_-_r...). The frame is the lighter metal object at the top above the top edge of one of the pads.