Carving Axe Grinds

I've put all kinds of grinds on various axes and hatchets over the years and can say that in general, for craft axes/hatchets, flat grinds perform the best in pretty much every situation. This is largely because flat bevels bite most intuitively, and allow you to precisely steer the cut and "drive a line" with repeated sequential blows into the same cut.  These flat grinds on carving axes are usually closer to 30 degrees (like chisels, drawknives, sloyds and pretty much every carving tool) rather than the typical 20 degree slight convex for general use axes. This is because general use axes are mainly intended to chop into large, heavy material.  They need to bite deep and remove large chips to work efficiently.  Thus they stick a little and have to be worked loose from the cut, which is no biggie if the sticking isn't too severe and the material being worked is heavy enough not to flop around as you try to pry the axe loose. Try carving a spoon with a hatchet that has fairly thin cheeks and a 20 degree slight convex, however, and not only will it stick enough that you lift the entire spoon blank up with the axe (suuuper annoying), but the relatively deep bite can be a danger to going past your lines. Put a 25 to 30 degree flat grind on that same hatchet, and you'll have a much better experience.  The more obtuse the grind angle the shallower the bite and the easier the release.  You can get away with a whole-cheek slight convex on a carver, but the effective grind angle right near the edge needs to be closer to 30 degrees – thus you need a fatter cheeked hatchet for that.  This situation has the advantage of much easier upkeep with just a file vs trying to maintain dead flat bevels with stones or abrasive paper.  If you have proper flat bevels, keeping them as flat as you can is crucially important, because even slight curvature over the small width of the bevel (vs the large span of the entire cheek in an overall slight convex grind) will cause lots of glancing blows as the crown of bevel curvature hits the workpiece instead of the edge with minuscule reductions in the angle of attack. In the end, it’s not a matter of absolutes, but of tradeoffs, and I’m certainly sympathetic if someone prefers OK geometry that’s easy to keep OK, over perfect geometry that’s a bugger to maintain.

Left: Whole-cheek slight convex grind, ~25 degrees at edge

Right: Flat grind, 27 degrees