[QUOTE=BluErf]Thanks to everyone for kind comments.
I love this sewar too.
Hi Lew - thanks for pointing that out. However, I always thought the extra black portion of the edge, running from 30% up the forte to the tip was a sign of the tempering. The metal at the edge looked rather homogenous, except for the extra black shade, which turns out with etching.
Hi BluErf
The hardened edge on your sewar does not exhibit a continuation of the pamor that we see on the rest of the blade. A temper line forms when one quenches a mono steel or pattern welded blade in oil or water this forms austinite or martinsite along the edge which appears as a temper line. Maybe one of the smiths here can explain it better than me?
Lew