Here is what could be a stupid question

[Delta Handmade Knives]

Can the presence of a hamon on a blade be taken as evidence that the edge has in fact hardened?

 

[John Wilson]

Can the presence of a hamon on a blade be taken as evidence that the edge has in fact hardened

That's not a dumb question at all. It at least shows that the edge is harder than the other side of the hamon. How much differential is required to get a visible hamon? I don't know. That's a good question for our resident hamon experts @johndoyle

 

[Kevin R. Cashen]

It can show that the edge is a different hardness, but it can't tell you how hard that edge is. One caveat is that it can show you how far the different phases are from the edge. ie. if a hamon dips to less than 1/4" from the edge it can be a clear warning sign.

 

[Delta Handmade Knives]

Thank you Gentlemen. Much appreciated.