Japanese steel types for beginners

What are the different steel types used in Japanese knives? What are their differences?

Now I am not going to list the steel compositions of every knife type and pretend you understand the differences! Even I don't!

I’m going to tell you about the differences I’ve noticed as a chef of almost 20 years and as a business owner selling Japanese knives.

These are my opinions base on my experience and my customers.
Feel free to argue in the comments.

At first it may seem a little confusing.
When you realize that there are only a few main types of steel used in Japanese knives, which are mostly made by the one company (Hitachi).

Japanese names vs English names.
The most annoying and confusing part………

Shirogami- White paper steel or commonly called white steel. Shiroi is white in Japanese.
White steel

Aogami- Blue paper steel or blue steel. Aoi is blue is Japanese.
Blue steel

Ginsan- Gin meaning silver, and san is the number 3. Also call silver3 steel.
Ginsan steel

Carbon steels: Non stainless steels

White steel/ Shirogami
White steel comes in numbered variations 1, 2 and 3.
The main difference between the variations is White #1 has the most carbon and as you progress down 2 and 3 have less and less carbon.
#1 steel is most common and has about 1.25-1.35% carbon and not much else.
#3=%0. 0.80-0.90
White steel #1 is known for taking a crazy sharp edge and being easy to sharpen.
Having not much other than iron and carbon this knife may rust easily without knife care.
*Remember to wipe down your knife when first get it until a patina builds up.

Now the one thing no one seems to tell you about white steel!
It tends to be more brittle.
Compared to other steels made by Hitachi white steel tends to chip, crack and snap easier.

Conclusion: As it stands white steel is still super popular with knife nerds around the world who know how to take care of their knives
and love it for its ease of sharpening and wicked edge retention, even if it comes at the cost of a little durability.

Blue Steel/ aogami

Blue steel like white steel comes in a few different variations: 1 & 2.
Same deal as white steel, #1 has more carbon and tends to be more brittle than #2.
(With the same amount of carbon respectively)
However blue steel in general has a lot more bits and pieces in its composition.
It has a tiny bit of chromium making it a tiny bit more resistant than white.
It also has tungsten(only in #2) phosphorus & sulphur!
These additions make the steel slightly more durable but less easy to sharpen.

Conclusion: Very similar to white. Less reactive than White steel but still requires care.
Same carbon content with a few additions making this steel easier to use and more durable.

Blue super steel/ aogami super
More carbon @ %1.40-1.50 than blue #1
Chromium means more corrosion resistance.
Tungsten and an addition of Vanadium making it stronger.
A knife maker recently said to me:
“………..it’s the only steel name that makes sense. If you know how to use it, it’s amazing!............”
It rusts less than white steel, but as a trade-off it is also harder to sharpen.
Super blue also tends to be one of the most expensive steels.

Conclusion: Regarded as Hitachi’s best carbon steel. Still requires care. Costs more.

Stainless Steels/ Semi stainless

Silver 3/ Ginsan
This is one of the most popular stainless steels with Japanese knife makers.
Very similar to white #2 in carbon content but with one main difference:
Chromium!  (%13-14.5)
Chromium is the corrosion resistant addition.
Easy to care for and one of the easier stainless steels to sharpen.
This comes at a cost.
Although ginsan is easier to sharpen than other stainless steels, it is still noticeably harder to sharpen than carbon steel alternatives. This is the price of corrosion resistance.

Conclusion: Stainless steel version of white steel.
Harder to sharpen. Ease of use with corrosion resistances.

Made by someone other than Hitachi steel!
Takefu Special Steel Co.,Ltd
Similar to ginsan but with Molybdenum, Vanadium, Cobalt and Manganese.
VG-10 is a one of the best stainless steels used by the Japanese craftsmen.
This steel is used in $150 knives like Tojiro and $600 handmade knives.

Conclusion: A great stain steel. Very similar to ginsan steel.
Tends to have a lower heat treatment and used in some mass-produced knives.

Other steels and unpopular steels

Swedish stainless steel
Considered a great stainless steel.
Similar composition to VG-10 without cobalt.

SLD Steel
Relatively new to me.
-Very high carbon content.
-Fantastic performance that rivals/surpasses ginsan.
-Classed as a semi stainless with %12 chromium.

Hap 40
I have only used this steel a little, but I would guess its somewhere in between a stainless steel and a carbon steel with only 3.70-4.70% chromium.
-Potentially vulnerable to rust and corrosion
-Very different to many steel compositions
-High heat treatments are possible

-Very high carbon context. 3%!!!
-High in chromium %20!
- Extremely high heat treatments possible up to 67RHC!
-This would be a pain to sharpen

Another steel made by Takefu Special Steel Co.,Ltd.
-Unpopular, yet a beautiful steel
-Harder to sharpen
-High hardness possible up to 64RHC
-Expensive to produce

Overall conclusion

All steels mentioned are considered some of the best in the world yet have subtle differences and effects from their composition.
Steel type is often used as a selling point but is just one part of an equation that adds to a great knife.
Other factors like the heat treatment and edge geometry also impact the way a knife performs, and how durable it is.

Still confused? Have more questions?

If you would like to read more about steel compositions head to Hitachi’s website:

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