I was in Michigan visiting my family there and my uncle wants me to make him a fillet knife he wants a 10 inch blade I haven't done much in the way of fillet knives and was wondering what steel I want to use stainless,what thickness and what hardness I posted in general discusions and got one reply of 3/32" thick and 57 rockwell any more suggestions or comments are appreciated

That sounds about right to me. 440C would be a good choice.