When working with design and manufacturing data it is frequently necessary to convert between the "Across Corners" and the "Across Flats" dimensions of hexagon bolt heads.
This is usually needed when dividing hexagons onto machined components. Given the spanner jaw AF size, one can find the minimum diameter AC to machine on the lathe before division of the hexagon.
It can also be useful when sizing bolts to a specific application, where there is limited space for a fastener. Given the space available, one can determine the maximum spanner jaw bolt size possible.
The two functions above allow computation of the two circle diameters that fit perfectly inside and outside an equal side length hexagon.
