I changed my first post in this thread to more accurately state that the casehead, and not the bolt face measures .473".
Although it is technically incorrect bolts are generally referred to be the size casehead they're designed for rather than the actual size of the bolt face itself.
Thus we have .378" bolts, .473" bolts, and .532" bolts among others but the actual measurement of the bolt face will be larger than that in every instance.