When I stamp my blades I first grind them to the 120-220 grit finish, and all holes for the handle drilled first.
Place blade on a level surface such as a flat anvil. (railroad rail 12 inches long makes a good flat anvil). Heat the area you wish to strike the stamp with a torch until cherry red.
With stamp secured to vise grips for a better hold, place stamp even and level to the heated surface of the tang and stike once with a regular hammer. You only get one shot at this. This can be a drawback as I have ruined a few good blades when my stamp was not even and level with the steel and the result left half of my name missing from the blade.
Then simply grind off any discoloration from the heating. Strike the name prior to heat treat. Works every time, and I have been using the same stamp for 20 years. I got the stamp made by the Evers stamping company somewhere near New York. I do not know if they exist anymore.