I was modifying a hardware-store hatchet and wanted to profile it for cutting rather than splitting. This left me wondering what was the proper range of angles.
A bit of googling took me to: https://www.bladeforums.com/threads/sooo-whats-the-proper-edge-angle.1342535/ which has two reference images. One of them resulted in a very weird profile (had an odd concave section near the tip), so this is “Hardwood” variant of this sheet:
Original source of this diagram is: https://www.fao.org/3/t0129e/t0129e.pdf
Well, time to go sharpen my hatchet….
The author hasn't provided the model origin yet.