My 'custom' billhook design. + pics! any black smiths??

[Samon]

Full flat grind would also make a fairly weak edge in comparrison to all that weight
I'd be tempted to go for 6-8mm and convex the edge.
At some point if you're swinging this you will miss hit the blow and the stronger the edge the more likely it is to survive

The ones i've worked with while labouring were ground somewhat convex, held an edge well but weren't as thick as i'd like mine to be so i guess a finer edge wouldn't fair so well for my ruggeg usage. What would a decent axe head be considered? (gb type)

 

[Buckshot]

Axes IIRC are slightly convex normally
Some are Scandi though bit I think most are convex
It allows more meat behind the cutting edge and therefore is stronger in use