Doug Lester
Well-Known Member
Thanks for reminding me of another way to harden just the edge of a blade. The thought behind my responce to Kevin was based on it didn't click in my mind that when one did a soft draw on the spine of a blade they were starting out with tempered martinsite and changing it to a softer temper and that the martinsite, even with the soft draw, was still stronger than the pearlite that would result from differential hardening. My comment about heating the spine with a torch until it was austinised to convert the tempered martinsite to pearlite was more to illustrate the impracticallity of doing so.
Doug Lester
Doug Lester