MCW
Somebody's talking crap here & it ain't the tree!
Cottonwood.
Which on itself is not hard at all, but this particular tree came from the German/ French border and had been around 100 years old. During WW2, the tree took in a lot of shell splinters, ruined a brand new Stihl chain in less than 10 minutes... :soldier:
I've heard of people hitting bullets etc but hitting shell fragments is something special - few countries can boast of having that sort of metal in trees