Hamon- I found a few

Recently I got Iwasaki Western Tamahagane, which is deferentially heat treated razor. Knowing that I decided I'll etch it with acid to make the Hamon stand up from the rest of the blade.

After a few soaks in hot vinegar and cleaning in between, and natural stone polish afterwards I got a pretty interesting hamon to show up.

http://i46.tinypic.com/59wjf6.jpg
http://i50.tinypic.com/68r52e.jpg
http://i46.tinypic.com/5yb4n6.jpg

Then the big surprise...
I was working on a FON Golden Star, from my "for restoration" stash, hand sanding to prep it for high mirror finish. I started with Aoto powder then 1k Aluinum Oxide powder, and saw that the steel of the blade has two distinct finishes meeting ~1/2 way -a sure sigh for a differential heat treatment.
So I put the blade trough the hot vinegar etch process and got a nice wide hamon. Whet I found really surprising is that a factory made razor has this kind of treatment, may be that was the way to achieve really high hardness of the edge. Needless to say this one stays in the collection, and I will have to check every single Japanese straight for hamon from now on :)

http://i49.tinypic.com/2n80oj9.jpg
http://i47.tinypic.com/2eaqvid.jpg
http://i46.tinypic.com/oqiuxx.jpg

Anyone that has blades with hamons post them so we can all enjoy them.

where did u get such a beauty

Wow, that is very cool!
I might just try that on one of my Fon's.
In fact, I feel very tempted to try on all my Japanese western grinded razors:)
Thanks for posting Stefan!

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Originally Posted by Birnando

Wow, that is very cool!
I might just try that on one of my Fon's.
In fact, I feel very tempted to try on all my Japanese western grinded razors:)
Thanks for posting Stefan!

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This is my plan for mine, I wonder how many will have it. I tried another blade which turned out did not have a hamon.

Nice, Stefan!! Kind of like a treasure hunt. I've always admired the hamon blades. One day.

Regards,

Howard

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Originally Posted by mainaman

This is my plan for mine, I wonder how many will have it. I tried another blade which turned out did not have a hamon.

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The hamon is the demarcation of the martensite into other crystalline structures at the transition zone. The blade without hamon is through hardened so the entire blade is martensite, or not, if it wasn't hardened, and you'd know that pretty quick, or it's of a kind of steel that has enough alloying elements to prevent a hamon from being visible. Chromium is one of those elements. :)

I had a sandwich with hamon it today, first I've heard of it on a razor. Thanks for the interesting info.

That is pretty cool. Always neat how sometimes you can just come across things by fluke.

Mike, or Stefan, Do you know if the blade edge is hardened, or if the blade SPINE is annealed? Curious if there are 2 different ways of achieving this goal, or if I am just being too imaginative with how it was accomplished. :)

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Originally Posted by Magpie

Mike, or Stefan, Do you know if the blade edge is hardened, or if the blade SPINE is annealed? Curious if there are 2 different ways of achieving this goal, or if I am just being too imaginative with how it was accomplished. :)

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I think the edge is hardened, the spine is covered in clay and when quenched will cool down slower than the edge. I believe this is essentially the same process as used to make katana.

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Anyone that has blades with hamons post them so we can all enjoy them.

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Oops did you mean razors ;)

They look pretty cool Stefan. :) The Fon's quite chunky. Not tamahagane is it ?

I often notice a 'line' on the tangs of old Sheffield blades during sanding and polishing - must be the same thing. Awesome hamon there Oz, I dream about finding the Honjo Masamune... ;)

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Originally Posted by onimaru55

Oops did you mean razors ;)

They look pretty cool Stefan. :) The Fon's quite chunky. Not tamahagane is it ?

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Oz swords are cool too.
The FON is stamped Extra Steel on the tang, I was surprised they did such heat treat in factory though.

The edge is hardened, always.
While it is very easy to drop the temperature of a part of a blade, it is very to do the reverse without also soaking heat in the rest of the blade where you really don't want the heat.

Btw and just to avoid the confusion: it is perfectly possible to achieve a hamon without even trying. The spine is very thick. The edge is thin. When the razor gets dunked in oil (presumably) the edge part will cool instantly while the thick spine will cool more slowly. Esp if oil is used, the spine will not get hard so much. There might be some surface hardness, but since the razor is ground after heat treatment, that would disappear with the grinding process, leaving you with a razor that has a soft spine, a hard edge, and a visible hamon if the steel did not have alloying elements that prevent the formation of a visible hamon.

It is even possible that they clamp the blade between plates to prevent yield loss due to warp. I bet that those FON razors were not really HTed with the intention to create a hamon. If they had, they would have made it visible. They didn't, which suggests that it is a side effect.

In fact, I did have a swedish steel razor made in Japan which had a temper line running through the tang where it had been clamped when it was quenched. The part between the clamp did not cool rapidly and was softer than the part of the tagn near the blade. If you are HTing simple carbon steel that has thin and thick portions, you are bound to get temper lines whether you want them or not.

Might be a fun experiment to do when my forge is up and running again, to see if a razor made from simple file steel gets temper lines or not.

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Originally Posted by Bruno

The edge is hardened, always.
While it is very easy to drop the temperature of a part of a blade, it is very to do the reverse without also soaking heat in the rest of the blade where you really don't want the heat.

Btw and just to avoid the confusion: it is perfectly possible to achieve a hamon without even trying. The spine is very thick. The edge is thin. When the razor gets dunked in oil (presumably) the edge part will cool instantly while the thick spine will cool more slowly. Esp if oil is used, the spine will not get hard so much. There might be some surface hardness, but since the razor is ground after heat treatment, that would disappear with the grinding process, leaving you with a razor that has a soft spine, a hard edge, and a visible hamon if the steel did not have alloying elements that prevent the formation of a visible hamon.

It is even possible that they clamp the blade between plates to prevent yield loss due to warp. I bet that those FON razors were not really HTed with the intention to create a hamon. If they had, they would have made it visible. They didn't, which suggests that it is a side effect.

In fact, I did have a swedish steel razor made in Japan which had a temper line running through the tang where it had been clamped when it was quenched. The part between the clamp did not cool rapidly and was softer than the part of the tagn near the blade. If you are HTing simple carbon steel that has thin and thick portions, you are bound to get temper lines whether you want them or not.

Might be a fun experiment to do when my forge is up and running again, to see if a razor made from simple file steel gets temper lines or not.

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I like the hamons cosmetically, the ones with more details especially.

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Originally Posted by Bruno

I bet that those FON razors were not really HTed with the intention to create a hamon. If they had, they would have made it visible. They didn't, which suggests that it is a side effect.

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I disagree.many Honyaki style chef knife intention to creat hamon but not for cosmetic just for quality of the cutting edge that why they woundn't have made it visible.