im interested in the differences between flat edged axes such as broadaxes and normal rounded edged hatchets and felling axes. as far as im concerned the rounded edge is closer than a flat one to a triangular point thus it has more penetration power. and as far as i can tell the flat axes are flat just to be able to have a flat piece of wood when done chopping. ive heard that a flat edge is best for dry or green wood and a curved axe is best for dry or green wood but i forget which edge shape went with what type of wood. as much wood as ive cut ive never noticed a major difference in this despite me rounding my broadaxe and still having heavy use.