Very off topic. I was trying to slice some fancy hard crust bread this afternoon. I wanted some nice even slices to go into the toaster. Trying the other day the knife got deflected by hard spots on the crust and skips around yielding uneven thicknesses. So I turned it upside down and got much nicer cuts with no deflection. I actually figured this out the other day when trying to slice some smoked cheese that had developed a hard rind on top.
I suppose this might help in machining areas with HAZ from welding.
Bill D