I love seeing a hamon line on swords and knives, think it is really cool. Usually they happen when two different steels are forge welded together or using a special clay laid on the blade to control the speed of hardening during quenching. You want the edge hard but with a softer spine and the clay acts like insulation on the spine to slow the cooling. To bring out the hamon line you have to use Ferric Cholride on the blade and then polish the hell out of it. Some bladesmiths get really fancy with their clay layout on the blade before heat treating, actually making patterns instead of just a line.

Well I don't forge weld, maybe down the road, or use clay, not really needed in my work BUT it is possible for me to get a hamon due to the way I quench some blades after heat treating, I do a differential treatment or edge quench, holding the hot blade somewhat horizontal I dip the edge into the oil and hold for a few seconds before dipping the whole knife. Now what happens next depends on how well I prepped the blade for heat treating, having a good flat blade helps. I had a blade sitting on the bench for the last couple of weeks waiting it's turn for handles and final sanding, it had a pretty decent blade and I thought I might just get lucky and get a hamon on this one, after a few minutes in the Ferric Cholride and more sanding with some polishing this is what I got.....

I am pretty tickled to get my first hamon line and it was well worth all the extra ware and tare on my elbows and forearms, tired but really happy after a long day.

Gunner

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