Thread: Kamijo Yukio, revealing the secrets of steel

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.

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.