Tempering and heat treating are two different things; you heat treat after primary grind and holes are all drilled then it is heat treated....after heat treating the knife is too hard and brittle, then you temper the blade normally depending on what Rockwell hardness you are trying to achieve. Normally 400 degrees for two hours, take out of oven let cool and repeat process.... then he finish grind can be done, followed with the sanding to the desired finish you want... For my mirror finish I start with 125 grit and take to 5000 grit.
Samples can be seen on my gallery on my webpage..
www.Jankcustomknives.com