Thread: Kamijo Yukio, revealing the secrets of steel

There's some good info about Mr Yukio Kamijo here (thanks Fikira)

https://historyrazors.wordpress.com/2016/12/08/iwasaki/

Now I have a few of these razors on the bench at the moment. I'll say, once they arrived and I opened the package, all my other projects got put aside immediatelly. I posted this on Instagram a few days ago.



Here it is clearly visible, the razor on the left got cleaned by someone with a rotary tool, leaving those ugly marks, which I assume are in the 400 grit range.

The razor on the right is a different story. It came with a proper polish, not top-katana-togishi grade, but I like it a lot. Tarnished and lightly pitted due to aging I suppose.



So I started playing around with the Dremel-polished razor. I took a piece of Chosera 1K and gave it some rubbing, to erase the old marks. Then I went ahead and used several other stones to mellow down the 1K marks. I used Botan, and a few (ji-to and ha-to) Uchigumori stones.

The outcome so far is this.


A few observations. I rushed through this and one of my stones scratched the steel. I think I know now which one, so I have a plan for remedy. I do not intend to completely remove the 1K marks... or rather, I won't kid myself, I'm no sword polisher. What I want to end up with is a clean polish that will display, what it displays now, which is how the handle of the razor was forged to meet the cutting edge. I won't attempt removing the pits, as that would require seriously coarse grinding.... well, not yet anyway.




I will add to the thread as I progress. I will also be showing the other one, as I'll try to alter its polish minimally, only to remove the tarnishing and attempt to bring out that same hardening line, which isn't visible at the moment.

Thanks for looking!

So there was a tiny inclusion in the piece of Uchigumori. Talk about a bad stone ruining your day! I needed to remove the scratches running lengthwise on the blade.

I've lapped through the Uchi and tried with the same stone, now clean but no luck, the scratches were too deep. In an attempt to find some reference as to the depth of those rogue scratches, I took a piece of an 8K stone. Not much progress, or very slow progress, so I decided this was somewhere in the 1-2K realm. I could go back and re-establish the base with 1K, but that would be too easy :P

Quick try with Botan nagura just to see... still too slow. Step back to Suita and I believe it's now looking a lot better. I'll need to spend some more time on this stone, before moving up. This is OK, at least I know which stone works at this stage.

Now finished the other side with my Chosera 1K. This time, I started with Chosera 600 to remove as much pitting as I'm comfortable with. You'll notice this side looks a lot cleaner and makes me wanna go back to the other face and repolish it completely.

Don't hold your breath gentlemen, this may turn out to be a long journey [emoji16]



Even on the 1K, it is clearly visible where the steel ends and the iron (I assume!) begins.

Getting somewhere. 1K face polished close to calling it done.

Originally Posted by Srdjan

Now finished the other side with my Chosera 1K. This time, I started with Chosera 600 to remove as much pitting as I'm comfortable with. You'll notice this side looks a lot cleaner and makes me wanna go back to the other face and repolish it completely.

Don't hold your breath gentlemen, this may turn out to be a long journey [emoji16]



Even on the 1K, it is clearly visible where the steel ends and the iron (I assume!) begins.

Were those made similar to traditional kamisori with soft iron and hard steel? I always thought they were one piece with differential heat threat, just like Iwasaki taught him.

Those two are top knotch....you got two of the bet out of the lot! Congratulations!
I have developed a passion for japanese razors over the years and amongst all Iwasaky and makers related or involved to Iwasaki razor production.

Iukio Kamijo made some exceptional razors.
One of his razors could have cost up to 30 times more then an Iwasaki when Iwasaki started producing razors.

Your two are mid production...and in exceptonal shape.

I was lucky enough over the years to aquire almost all of iwasaki's razor models....and his colaborations with Kamijo and Tanifiji.

These 2 are some late production Yukio Kamijo @20 and 22 mm wide.
They were found in pretty bad shape and have been reground by an old man in my country that is a 5th generation solingen Grinder.
these 2 are ofc before Yukio started colaboration with Iwasaki.

After the colaboration began...the razors were stamped by both masters.
This one is my most valued razor atm... a first generation Iwasaki Kokusen + Yukio Kamijo Tamahagane western grind.
@ 21,5 mm wide and minimum honeware...i have no idea if it was the factory edge on but it looks pritty mint.


The 2 also made sweedish steel western razors that were stamped with both masters markings.



The razors made in colaboration with Kamijo were quenched verticaly and that means the spine is also hard and more ware resistant...
After the colaboration with Kamijo ended Iwasaki strted quenching the razors horizontaly like katana swords...so these later versions actualy have a softer spine prone to honeware and just 2/3 of the blade width hardened


This is a Kamijo quench


this is another Kamijo quench

So after the Kamijo colaboration iwasaki started to quench the blades horizontaly similar to katana ...


...also the Tamahagane recipe or heat treatment changed after ending the colaboraton with Kamijo.

The tamahagane made in colaboration with Kamijo is something you have to test to understand....it is a bit softer then later iwasaki tamahagane...but honing is child's play and it takes a sublime edge so easily.

After Kamijo colab ended Iwasaki wanted harder Tamahagane so he altered the heat treatment and possibly the recipe too. Resulting steel was indeed harde and fine grained but some excepionaly hard blades 64-67 HRC were difficult to sharpen and prone to chipping.
Also the shaves they provide are not that impressive....or maybe i did not manage to get the best out of them...who knows...i like the old tamahagane better even if it is slightly softer. @ 62-63 hrc(tested).

After Kamijo retired Iwasaki started colaborating with master Tanifuji Fukutaro who took over finishing and scaling the razors forom Kamijo.

This is the generation that Tamahagane razors got progresively harder...and all western ground razors were horizontaly quenched.
I was lucky enough to have a few of the razors from this time period:


A iwasaki Tamhagane and an Iwasaki no. 90 from this period.

Also an Iwasaki Wedge from that period...these are a bit rare because from my understanding...during Kamijo colaboration wedge grinds were more frequent then in the Tanifuji colab period when they became less and less manufactured.

This is exactly the type of response I was looking for, with lots of pictures and explanations. Thank you, Cotiga!

I actually started polishing with stones to reveal the quenching line, because I know some of them were quenched like swords and that just looks awesome. Still, these are in fantastic shape and quite special.

Stefan, I actually don't think this is iron anymore, having rubbed it with at least 5 different stones. It's not as soft as iron on a kamisori. Probably DH, as you said.

No, Thank you for sharing these with us,
They are rare beautyes and few ppl have a chanse of owning one ...let alone two.

I would sugest testing the blades with the tap and woble test and if there are geometry issues send them for a regrind to Karl Jhonson...he does exceptional work on regrindin wedges and some of the best resto work arround...he can put a perfect geometry on them.

There's an interesting storry to the kamisory line and production but i would stray away from the subject too far.
I have managed to get my hands on an early Iwasaki Tamahagane Kamisory...one in Iwasaki Kokusen experimental steel(iwasaki tried to make a better steel then tamahagane but it was dropped due to hardness of shrpening and chipping) ...and one in sweedsh steel made by Shigeioshi.
This one is an old tamahagane...it seen a lot of use but it takes one of the best edges i have seen.


And this one is one in experimental steel...few were made.
It is exceptionaly hard and difficult to sharpen but i have managed to get a superb edge out of it after a few tries.
i can see why it was abandoned...i love honing and i hone a lot of razors but this one had me doubt my abilities.

.

The one in sweedish steel i have no pictures made ...perhaps another time.

Originally Posted by Srdjan

Stefan, I actually don't think this is iron anymore, having rubbed it with at least 5 different stones. It's not as soft as iron on a kamisori. Probably DH, as you said.

the hamon should show really well if you polish with Uchigomori

I did two Iwasaki, back in the day with simple sic powder and lemon juice etch and got very nice results.