Well it all depends on what you are going to finish it to after the heat treatment. When I am planning on a mirror polish, I mirror polish the blank before heat treatment. If I am planning a bead blasted blade, i take the blank to a 400 satin to remove all the scratches before heat treat, so all I have to do is get it back and blast it again. For a hand rubbed finish, i take it to mirror polished and then heat treat, and when the blade is ready I will take it backwards through the grits to get to the hand rubbed finish that i am looking for..
Alan..