After heat treat you may have light forge scale and baked on oil. It will scratch off with a file and is not an indication of blade hardness. If you run a file across the edge and it’s skates then the blade has hardened.
Hello,
A little about me. I have had my shop set up for about 18 months. It is just a hobby now but I have finally produced a knife I was proud of. I am sure there are still many mistakes in my future but this is fun and great therapy.
Thanks for letting me join,
David