Is there risk of the high carbon edge insert failing? Is the thing strong enough to be used by a professional logger or for chopping winter wood?
Hank,i'm sorry,but the Title of this thread is odd:
"Cast steel"(steel obtained by melting the ingredients together,crucible steel,et c.) was the material used for the Insert,not the "head".
The "head"/body/all other parts BUT the cutting edge was normally some sort of then-current low-Carbon steel,and the entire enchilada was Forged,and forge-Welded,the cast-steel edge likewise forge-welded in(or around)the other forging.
So are you asking how often the edge itself fractured?
Or how often it de-laminated from the rest of the head?
Or?...
In the very general scheme of things Brent is correct,Not often,and usually under extreme duress.
It was a good,reliable method of axe manufacturing,with many examples still around and fully functioning.