Blue Steel #1 - High Carbon Steel
Blue Steel is regarded by many as one of the pinnacles of edge retention and hardness in Japanese kitchen knives. You may see them being used in high end restaurants, and their cutting power is something we believe everyone should experience at least once in their lives if they can. This blog will go into detail as to how Blue Steel #1 might be a steel for your next knife worth considering!
Blue Steel #1 (Aogami 1) - Outstanding Edge Retention
Blue Steel (also called Aogami) is a material created by adding chromium and tungsten to White Steel, which enhances the steel's resistance to wear and tear damage. Among the Blue Steels available, Blue Steel #1 is most well known for its high carbon content and sharp cutting edge.
High potential, but not beginner friendly
It’s difficult to recommend Blue Steel #1 to first-time carbon steel knife buyers, especially if they plan on maintaining the knife themselves.
Due to its high hardness levels, a forged Blue Steel #1 kitchen knife is more resilient against wear and tear as stated earlier. However, this also includes reslience against sharpening the blade itself as sharpening involves shaving the blade down. Due to this abrasive resistance, the steel can potentially slip on whetstones during sharpening. In other words, Blue Steel #1 is a material more suited to users who already have experience and skill with using and maintaining carbon steel kitchen knives. While beginners can still use the blade, they will find maintaining it to be significantly more challenging.
Despite a limited userbase, its exceptional cutting power is attractive
When slicing sashimi with a Blue Steel #1 knife, the blade will "pull cut" through effortlessly, with an almost frightening level of smoothness.
Due to Blue Steel knives being forged thoroughly, they retain amazing strength and flexibility even with an extremely thin blade. You almost can’t feel it cutting as it slices through!
If sharpened correctly, you won’t need to apply much hand strength when cutting either, allowing you to prepare dishes with minimal strain on the ingredients and your hands. A Blue Steel #1 knife can be considered a knife that will truly take you to the next level of culinary arts.
Steel Mapping Comparison
Steel material is crucial for indicating a knife's initial performance (amongst many other things related to craftsman ability and more). Below are some comparisons to give you some understanding showing what a particular step of the process does in terms of impacting sharpness, balance and maintainability.
Steel Material | Heat Treatment/Forging | Edge Sharpening | Handle Attachment | |
Sharpness | ○ | ◎ | ◎ | |
Balance | | △ | △ | ◎ |
Maintainability | ◎ | ○ | ○ | |
Steel Material | Heat + Forging | Making Edges | Handle Attach. | |
Sharp. | ○ | ◎ | ◎ | |
Bal. | | △ | △ | ◎ |
Maint. | ◎ | ○ | ○ | |
There’s three key pointers in the above chart to focus on.
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Steel Material has a large impact on sharpness and maintainability (ease of sharpening and resistance to rust).
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Apart from sharpness, heat treatment and the sharpening process in knife creation also have a large impact on sharpness.
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Measuring a knife’s strengths is more than just its sharpness. Balance and maintainability also need to be considered.
Based on the above steel mapping chart, Blue Steel #1 falls in this position on the graph below:
Amongst the steel knives manufactured in Japan, Blue Steel #1 falls on the higher side price-wise. It can be considered somewhat similar to White Steel #2 with a higher toughness and hardness rating. Also, it maintains its sharpness for a long time, again superior to White Steel #2.
However, this conversely makes these knives more difficult to sharpen. It’s a knife type for those who are okay with sparing no expense to whetstones and with effort to sharpening. In other words, if you don’t want to spend time sharpening and caring for your knife - this steel is perhaps not the one for you.
If you do come across a Blue Steel #1 knife that is easier to sharpen, it may have intentionally gone under a heat treatment in order to reduce its hardness.
A steel for those who enjoy sharpening and knife maintenance
Composition Comparison
Let’s compare Blue Steel #1 to other well known steel products via the table below.
- MAJOR MATERIALS
- SECONDARY MATERIALS
Manufacturer | Steel Name | Carbon | Silicon | Cobalt | Phosphorus | Sulfur | Manganese |
| Effect of Material | Hardness | Hardness (⅒ of Carbon) | Decarburization Prevention | Embrittlement | Embrittlement | Sulfur Removal |
| Listed Value | Average | Maximum | Average | Maximum | Maximum | Average |
Hitachi Metals | Yellow Steel #2 | 1.1 | 0.15 | | 0.03 | 0.006 | 0.25 |
Hitachi Metals | White Steel #3 | 0.9 | 0.2 | | 0.025 | 0.004 | 0.25 |
Takefu Special Steel | White Steel #2 | 1 | Undisclosed | | Undisclosed | Undisclosed | Undisclosed |
Hitachi Metals | White Steel #2 | 1.1 | 0.15 | | 0.025 | 0.004 | 0.25 |
Hitachi Metals | White Steel #1 | 1.3 | 0.15 | | 0.025 | 0.004 | 0.25 |
Hitachi Metals | Blue Steel #2 | 1.1 | 0.15 | | 0.025 | 0.004 | 0.25 |
Hitachi Metals | Blue Steel #1 | 1.3 | 0.15 | | 0.025 | 0.004 | 0.25 |
Hitachi Metals | Blue Steel Super | 1.45 | 0.15 | | 0.025 | 0.004 | 0.25 |
JIS Standard | SK4 | 0.95 | 0.2 | | 0.03 | 0.03 | 0.25 |
Hitachi Metals x Masahiro | ZCD-U | 1.05 | Undisclosed | | Undisclosed | Undisclosed | Undisclosed |
Manufacturer | Steel Name | Molybdenum | Vanadium | Nickel | Tungsten | Copper | Chromium | Hardness Rockwell Counter (HRC) |
| Effect of Material | Wear Resistance | Wear Resistance | Toughness | Wear Resistance | Antibacterial Effects | Anti-Corrosion | Changes in the quenching process |
| Listed Value | Average | Average | Average | Average | Maximum | Average | |
Hitachi Metals | Yellow Steel #2 | | | | | | | 56 |
Hitachi Metals | White Steel #3 | | | | | | | 55 |
Takefu Special Steel | White Steel #2 | | | 1 | | | 0.3 | 60 |
Hitachi Metals | White Steel #2 | | | | | | | 61 |
Hitachi Metals | White Steel #1 | | | | | | | 66 |
Hitachi Metals | Blue Steel #2 | | | | 1.25 | | 0.35 | 61 |
Hitachi Metals | Blue Steel #1 | | | | 1.75 | | 0.4 | 65 |
Hitachi Metals | Blue Steel Super | | 0.4 | | 2.25 | | 0.35 | 67 |
JIS Standard | SK4 | | | 0.25 | | | 0.3 | 55 |
Hitachi Metals x Masahiro | ZCD-U | | Contains | | Contains | | | 59 |
- MAJOR P1
- MAJOR P2
- SECONDARY P1
- SECONDARY P2
Maker | Steel Name | Carbon | Silicon | Cobalt |
| Effect | Hard. | Hard. (⅒ Carbon) | Decarb Pvnt. |
| Listed Value | Average | Max | Average |
Hitachi Metals | Yellow Steel #2 | 1.1 | 0.15 | |
Hitachi Metals | White Steel #3 | 0.9 | 0.2 | |
Takefu Special Steel | White Steel #2 | 1 | Not Stated | |
Hitachi Metals | White Steel #2 | 1.1 | 0.15 | |
Hitachi Metals | White Steel #1 | 1.3 | 0.15 | |
Hitachi Metals | Blue Steel #2 | 1.1 | 0.15 | |
Hitachi Metals | Blue Steel #1 | 1.3 | 0.15 | |
Hitachi Metals | Blue Steel Super | 1.45 | 0.15 | |
JIS Std. | SK4 | 0.95 | 0.2 | |
Hitachi Metals x Masa- | ZCD-U | 1.05 | Not Stated | |
Maker | Steel Name | Phos. | Sulfur | Mang. |
| Effect | Embrittlement | Embrittlement | Sulfur Rmvl. |
| Listed Value | Max | Max | Average |
Hitachi Metals | Yellow Steel #2 | 0.03 | 0.006 | 0.25 |
Hitachi Metals | White Steel #3 | 0.025 | 0.004 | 0.25 |
Takefu Special Steel | White Steel #2 | Not Stated | Not Stated | Not Stated |
Hitachi Metals | White Steel #2 | 0.025 | 0.004 | 0.25 |
Hitachi Metals | White Steel #1 | 0.025 | 0.004 | 0.25 |
Hitachi Metals | Blue Steel #2 | 0.025 | 0.004 | 0.25 |
Hitachi Metals | Blue Steel #1 | 0.025 | 0.004 | 0.25 |
Hitachi Metals | Blue Steel Super | 0.025 | 0.004 | 0.25 |
JIS Std. | SK4 | 0.03 | 0.03 | 0.25 |
Hitachi Metals x Masa- | ZCD-U | Not Stated | Not Stated | Not Stated |
Maker | Steel Name | Molyb. | Vanad. | Nickel |
| Effect | Wear Res. | Wear Res. | Tough. |
| Listed Value | Average | Average | Average |
Hitachi Metals | Yellow Steel #2 | | | |
Hitachi Metals | White Steel #3 | | | |
Takefu Special Steel | White Steel #2 | | | 1 |
Hitachi Metals | White Steel #2 | | | |
Hitachi Metals | White Steel #1 | | | |
Hitachi Metals | Blue Steel #2 | | | |
Hitachi Metals | Blue Steel #1 | | | |
Hitachi Metals | Blue Steel Super | | 0.4 | |
JIS Std. | SK4 | | | |
Hitachi Metals x Masa- | ZCD-U | | Has | |
Maker | Steel Name | Tung. | Copper | Chrom. |
| Effect | Wear Res. | Antibac. | Anti-Corrosion |
| Listed Value | Average | Max | Average |
Hitachi Metals | Yellow Steel #2 | | | |
Hitachi Metals | White Steel #3 | | | |
Takefu Special Steel | White Steel #2 | | | 0.3 |
Hitachi Metals | White Steel #2 | | | |
Hitachi Metals | White Steel #1 | | | |
Hitachi Metals | Blue Steel #2 | 1.25 | | 0.35 |
Hitachi Metals | Blue Steel #1 | 1.75 | | 0.4 |
Hitachi Metals | Blue Steel Super | 2.25 | | 0.35 |
JIS Std. | SK4 | | | 0.3 |
Hitachi Metals x Masa- | ZCD-U | Has | | |
Comparing to Hitachi Metal’s White Steel #2 which is the most popular knife steel for Japanese cuisine knives, we can see that Blue Steel #1 has a higher carbon content. It also has a higher tungsten and chromium content than Blue Steel #2.
These contribute to the excellent edge retention, flexibility and toughness Blue Steel #1 is known for. On the other hand, due to its very high wear resistance, while it can maintain its sharpness for a long time it also can be very challenging to sharpen. Choosing the right whetstone and demonstrating patience when you do sharpen it is required.
Buying a Blue Steel #1 kitchen knife
Blue Steel #1 truly shines in settings like high-end sushi restaurants, where the art of creating precise flavors and mouthfeels through sharp and clean cuts is paramount to the dining experience.
On the flip side, due to its higher carbon content this steel is very susceptible to rusting. The high hardness levels also make knives using this material vulnerable to low temperatures and impact damage like drops. It’s a premium material, but also requires delicate handling and careful usage.
It's important to note that this steel isn’t suitable for everyone due to its difficulty with maintenance. You may need to reconsider the whetstones you have and possibly purchase new ones. However, through the steady process of sharpening and cutting with the blade, you will steadily develop the skills to utilize the advantage of its hardness and toughness.
A skilled chef moves the blade swiftly and delicately, without any muscle strain. They work efficiently without exerting unnecessary force, ensuring minimal stress on the ingredients and thus improving the mouthfeel. Achieving this level of skill is only possible when you make a good knife using Blue Steel #1 your own.
For those who aspire to become a top-tier chef, this steel is one of the best.
Conclusion
Let’s recap the three key points related to Blue Steel #1.
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Blue Steel #1 is a high-end steel known for its high hardness and resistance to wear.
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Patience is required for sharpening, and you may need to reconsider your choice of whetstones or buy new ones.
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This steel is highly recommended for those aspiring to become top-tier chefs.
If you have further questions about Blue Steel #1, don't hesitate to ask us! We carry a very large selection of Blue Steel knives, and our experts can help you find what is best for you, and even if this steel is ideal for your needs.