The Beginner's Guide to Japanese Knife Steel: Shirogami, Aogami, and VG-10 Explained

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Why Steel Choice Matters More Than Brand

Source: Pixabay - Free license

Walk into any Japanese knife shop — whether it's a specialty store in Kappabashi or an online retailer — and you'll immediately encounter a wall of terminology: Shirogami #1, Aogami #2, Aogami Super, VG-10, SG2, Ginsan, ZDP-189. It can feel like you need a metallurgy degree just to buy a kitchen knife.

But here's the thing: the steel in your blade determines almost everything about how that knife performs. It controls the maximum sharpness, how long the edge lasts, how easy it is to resharpen, and whether you'll spend time after every cooking session drying your blade to prevent rust. Two knives with identical shapes from the same maker can feel completely different if one uses Shirogami and the other uses VG-10.

This guide focuses on the three steels that matter most for someone entering the world of Japanese knives: Shirogami (white paper steel), Aogami (blue paper steel), and VG-10. Together, they account for the vast majority of Japanese knives sold both domestically and internationally. Master these three and you'll understand the fundamental trade-offs that govern every Japanese blade.

All technical data in this article comes from Japanese-language sources, including manufacturer specifications from Hitachi Metals (now Proterial), educational materials from Tojiro, Jikko (堺實光), Ichimonji Mitsuhide (堺一文字光秀), and specialty knife retailers like Maruyoshi Hamono.

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The Hitachi Metals Origin Story

Where Japanese Knife Steel Actually Comes From

Almost every piece of carbon steel in a Japanese kitchen knife traces back to a single source: Hitachi Metals' Yasugi Works in Shimane Prefecture (now operating under the name Proterial after a corporate rebrand). This factory has been producing specialty steels since 1899, and their Yasuki Hagane (安来鋼) brand is the benchmark for the entire Japanese knife industry.

The Yasugi Works sits in a region with ancient connections to steel-making. Shimane Prefecture was historically the center of tatara iron smelting — the traditional Japanese method that produced the tamahagane steel used in samurai swords. Modern Yasuki steel isn't made by tatara methods, but the region's deep metallurgical knowledge informed the development of these purpose-built knife steels.

Why the Colored Paper Names?

The naming convention — "white paper," "blue paper," "yellow paper" — comes from the colored paper wrappers used at the Yasugi factory to identify different steel grades during production and shipping. White paper wrapped the purest carbon steel. Blue paper wrapped the alloy-enhanced version. Yellow paper wrapped the more affordable grade. The names stuck, and today they're the universal language of Japanese knife steel (Source: Maruyoshi Hamono, "Wabocho no Kozai no Shurui").

The hierarchy, from most accessible to most premium:

• Kigami (Yellow Paper Steel): Entry-level carbon steel, most affordable
• Shirogami (White Paper Steel): High-purity carbon steel, professional grade
• Aogami (Blue Paper Steel): Alloy-enhanced carbon steel, premium grade
• Aogami Super: Maximum performance carbon steel, the pinnacle

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Shirogami (White Paper Steel): Pure Carbon, Pure Edge

Composition and Grades

Shirogami is carbon steel in its purest practical form. Hitachi Metals produces it by removing impurities from the base steel until the carbon content is the primary determinant of performance. The result is a steel that responds beautifully to heat treatment and produces an edge of exceptional sharpness.

Shirogami comes in three grades, differentiated by carbon content:

Grade	Carbon Content	Hardness (HRC)	Character
Shirogami #3	0.80–0.90%	~61–63	Softest, most forgiving
Shirogami #2	1.05–1.15%	~63–65	The standard; most widely used
Shirogami #1	1.25–1.35%	~65–66	Hardest; longest edge retention

(Source: Jikko Cutlery, "Hocho no Hagane no Zaishitsu — Hagane no Shurui"; Ichimonji Mitsuhide, "Hocho no Sozai Shiro-ichi-ko")

Shirogami #2 is by far the most common grade in Japanese kitchen knives. Jikko describes it as "a representative high-grade blade steel used in wa-bocho" that delivers "sharp cutting ability, moderate flexibility, long-lasting edges, and easy sharpening — qualities that allow skilled craftsmen to create superior knives" (Source: jikko.jp, carbon steel knowledge page).

Shirogami #1, with its higher carbon content, achieves an impressive HRC 66 hardness. The Ichimonji Mitsuhide knife shop describes it as having "extremely high hardness" and notes that it's a steel that "removes impurities to the absolute limit" — making it the purest knife steel commercially available (Source: hocho.ichimonji.co.jp, Shiro-1 material page).

Shirogami's Strengths

Sharpest possible edge. Because Shirogami has minimal alloying elements, its grain structure is extremely fine and uniform. This allows it to take and hold an edge at very acute angles. Many professional sharpeners consider Shirogami the easiest steel to bring to absolute razor sharpness.

Easiest to sharpen. The absence of hard carbides from alloying elements like tungsten or chromium means Shirogami responds quickly to whetstones. A few minutes on a 1000-grit stone is often enough to restore a working edge. For chefs who sharpen daily before service, this matters enormously. Learn the proper technique in our whetstone sharpening guide.

Excellent kaeri (burr) feedback. When sharpening, Shirogami produces a clean, easily detectable burr that tells you exactly when you've raised the edge. This makes it the most "educational" steel for someone learning to sharpen by hand.

Shirogami's Limitations

Rusts quickly. With virtually no chromium content, Shirogami has zero corrosion resistance. Leave a Shirogami knife wet on the cutting board for 10 minutes and you'll see orange spots forming. Professional chefs who use Shirogami knives keep a dry towel on their cutting board and wipe the blade between every few cuts.

Requires skill to heat-treat. The lack of alloying elements means Shirogami has a very narrow window for optimal heat treatment. If the smith overheats or underheats during hardening, the performance suffers dramatically. Jikko's educational materials specifically note that "white paper steel is difficult to harden, and the differences in craftsmen's skill levels become readily apparent" (Source: jikko.jp). This is why a Shirogami knife from a skilled maker vastly outperforms one from a mediocre workshop.

Lower chip resistance. At high hardness levels, Shirogami can be brittle. Lateral stress (like twisting the blade while cutting through a hard squash) can cause micro-chipping along the edge. Proper cutting technique is essential.

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Aogami (Blue Paper Steel): The Alloy Advantage

Source: Hocho-Knife.com

Composition and Grades

Aogami starts with the same base as Shirogami #2 but adds two critical alloying elements: chromium (Cr) and tungsten (W). These additions fundamentally change the steel's behavior — they form hard carbide particles within the steel matrix that resist abrasion and extend edge retention significantly.

Grade	Carbon	Chromium	Tungsten	Hardness (HRC)	Character
Aogami #2	1.05–1.15%	0.20–0.50%	1.00–1.50%	~63–65	Balanced; most popular blue steel
Aogami #1	1.25–1.35%	0.20–0.50%	1.50–2.00%	~65–66	Harder, longer edge retention
Aogami Super	1.40–1.50%	0.30–0.50%	2.00–2.50%	~66–67	Maximum hardness; top-tier

(Source: damascus-houchou.com, "Hocho no Kozai" composition tables; Tojiro, "Zairyo no Shurui" material reference)

Aogami Super deserves special attention. With carbon content up to 1.50% and elevated chromium and tungsten levels, it achieves an extraordinary HRC 67 — the highest hardness of any carbon steel in the Hitachi lineup. The specialty knife site damascus-houchou.com describes it as "the pinnacle of the Hitachi Metals white paper and blue paper series, with the highest hardness among carbon steels" (Source: damascus-houchou.com, Aogami Super section).

Aogami's Strengths

Superior edge retention. The tungsten and chromium carbides embedded in the steel matrix resist wear far better than the pure iron-carbon structure of Shirogami. An Aogami blade will hold a working edge through significantly more cutting before needing resharpening. Jikko's comparison page states that blue steel "excels in edge retention, and provides a good balance of cutting ability, durability, and ease of sharpening" (Source: jikko.jp, "Aogami Shirogami Dochira wo Erabu?").

Better chip resistance. The alloying elements give Aogami a degree of "toughness" or flexibility (nebari) that Shirogami lacks. The blade edge is less likely to micro-chip when encountering hard ingredients or slight technique errors. This makes Aogami a more forgiving steel for everyday professional use.

Still hand-sharpenable. Despite being harder than Shirogami, Aogami responds well to natural and synthetic whetstones. It takes longer to sharpen than Shirogami, but the process is straightforward for anyone with basic whetstone skills.

Aogami's Limitations

Still rusts. The small amount of chromium in Aogami is nowhere near the 12-13% minimum needed for stainless classification. Aogami knives require the same careful drying and maintenance as Shirogami, though some users report very slightly better corrosion resistance in practice.

Harder to sharpen than Shirogami. The very carbides that give Aogami its edge retention also make it more resistant to abrasion on the whetstone. You'll spend more time and effort during sharpening sessions, and finer-grit finishing stones become more important to achieve a polished edge.

Higher cost. The additional alloying elements and more complex heat treatment requirements make Aogami knives more expensive than equivalent Shirogami models. The price premium for Aogami Super can be substantial.

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VG-10 (V Gold 10): The Stainless Benchmark

Composition and Character

VG-10 occupies a completely different category from the paper steels. Developed by Takefu Special Steel (based in Echizen, Fukui Prefecture — the same region famous for Echizen forged blades), VG-10 is a high-carbon stainless steel designed specifically for premium cutlery applications.

Property	Value
Carbon	0.95–1.05%
Chromium	14.50–15.50%
Molybdenum	0.90–1.20%
Vanadium	0.10–0.30%
Cobalt	~1.50%
Hardness (HRC)	~60–62

(Source: damascus-houchou.com, "V-Kin 10-go no Merit/Demerit"; Ichimonji Mitsuhide, VG-10 material page)

The "V" stands for a designation by Takefu Special Steel, and the "Gold" indicates premium grade. The cobalt addition is particularly notable — it improves heat treatment response and allows the steel to achieve higher hardness while maintaining corrosion resistance. The high chromium content (14.5–15.5%) comfortably exceeds the stainless threshold, meaning VG-10 will not rust under normal kitchen conditions.

Ichimonji Mitsuhide's material guide describes VG-10 as "a blade steel that combines the advantages of both carbon steel and stainless steel — it cuts well like carbon steel, and is also resistant to rust like stainless steel, making it an ideal knife steel" (Source: hocho.ichimonji.co.jp, VG-10 page).

VG-10's Strengths

Corrosion resistance. This is the primary reason VG-10 exists. You can slice tomatoes, wash the knife, and leave it in the drying rack without worrying about rust spots. For home cooks who don't want to adopt the professional chef's habit of constant blade wiping, this is transformative.

Excellent balance of properties. VG-10 hits a sweet spot: sharp enough for precise kitchen work, hard enough to hold an edge through a full cooking session, tough enough to resist chipping during normal use, and easy enough to sharpen with standard whetstones. The damascus-houchou.com review site notes that it offers "excellent balance of cutting ability, edge retention, and durability, and is loved by professionals as well" (Source: damascus-houchou.com, VG-10 review).

Global availability. VG-10 is the most common steel in Japanese knives sold internationally. If you walk into a knife shop in New York, London, or Sydney and pick up a Japanese knife, there's a good chance it's VG-10 or a VG-10 core clad in Damascus steel.

VG-10's Limitations

Cannot match carbon steel sharpness. The chromium carbides that provide rust resistance also create a coarser grain structure than Shirogami or Aogami. The result: VG-10 can get very sharp, but it can't reach the absolute razor edge that a pure carbon steel achieves. For professional sashimi work where the finest possible edge determines food quality, carbon steel still wins.

Lower maximum hardness. At HRC 60–62, VG-10 is significantly softer than Aogami Super (HRC 67) or even Shirogami #1 (HRC 66). This means VG-10 edges dull faster under heavy use, though the difference matters more to professional chefs cutting for 8 hours straight than to home cooks.

Less satisfying to sharpen. Stainless steels produce a "gummy" or "sticky" feeling on whetstones compared to the clean, crisp feedback of carbon steels. This is purely a sensory preference, but many sharpening enthusiasts find carbon steel more enjoyable to work with. Our sharpening guide covers technique adjustments for stainless knives.

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Steel Comparison Table

Property	Shirogami #2	Shirogami #1	Aogami #2	Aogami #1	Aogami Super	VG-10
Carbon %	1.05–1.15	1.25–1.35	1.05–1.15	1.25–1.35	1.40–1.50	0.95–1.05
Chromium %	Trace	Trace	0.20–0.50	0.20–0.50	0.30–0.50	14.5–15.5
Tungsten %	—	—	1.00–1.50	1.50–2.00	2.00–2.50	—
Hardness (HRC)	63–65	65–66	63–65	65–66	66–67	60–62
Edge sharpness	★★★★★	★★★★★	★★★★☆	★★★★☆	★★★★☆	★★★☆☆
Edge retention	★★★☆☆	★★★★☆	★★★★☆	★★★★★	★★★★★	★★★☆☆
Ease of sharpening	★★★★★	★★★★☆	★★★★☆	★★★☆☆	★★★☆☆	★★★☆☆
Rust resistance	★☆☆☆☆	★☆☆☆☆	★☆☆☆☆	★☆☆☆☆	★☆☆☆☆	★★★★★
Toughness	★★★☆☆	★★☆☆☆	★★★★☆	★★★☆☆	★★★☆☆	★★★★☆
Price level	$$	$$$	$$$	$$$$	$$$$$	$$$

Run your own comparisons with our steel comparison tool.

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How to Choose Your Steel

Source: Hocho-Knife.com Source: Pixabay - Free license

Choose Shirogami if...

• You sharpen your knives regularly (daily or every few uses) and enjoy the process
• You want the absolute sharpest possible edge for precision work like sashimi
• You understand and accept the maintenance commitment (dry immediately, oil periodically, store carefully)
• You're buying a traditional single-bevel wa-bocho for specific Japanese cuisine tasks
• You value the connection to centuries-old Japanese knife-making tradition

Choose Aogami if...

• You want carbon steel performance with better edge retention for longer work sessions
• You're a professional who needs a blade that stays sharp through a full service without resharpening
• You're willing to pay a premium for the "best of both worlds" in the carbon steel category
• You want the Aogami Super experience — the hardest, longest-lasting carbon edge available
• You already have sharpening skills and don't mind a slightly harder stone session

Choose VG-10 if...

• You're buying your first serious Japanese knife and want a forgiving, low-maintenance option
• You cook at home and don't want to worry about rust management after every session
• You want a knife that can go in the dish rack without consequences
• You need a double-bevel gyuto or santoku for general-purpose Western and Japanese cooking
• You want to find your knife easily — VG-10 options are available everywhere, from Kakaku.com's top rankings to international retailers

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Beyond the Big Three: Other Steels Worth Knowing

While Shirogami, Aogami, and VG-10 cover the vast majority of Japanese knives, a few other steels appear frequently enough to mention:

Ginsan (Silver #3 / Gin-san-ko): A stainless steel from Hitachi Metals that sharpens almost as easily as Shirogami while providing rust resistance. Often called the "stainless Shirogami." Gaining popularity among makers who want to offer a low-maintenance option without sacrificing sharpening feel.

SG2 / R2 (Super Gold 2): A powder metallurgy stainless steel that achieves HRC 63–64 — harder than VG-10 while maintaining stainless properties. Used in premium knives from makers like Shun, Miyabi, and various Sakai workshops. More expensive but represents the cutting edge of stainless knife steel.

ZDP-189: An ultra-high-carbon stainless steel reaching HRC 67 — rivaling Aogami Super in hardness while resisting rust. Extremely difficult to sharpen. Made by Hitachi Metals for specialist applications. Used in some premium Sakai and Seki knives where maximum edge retention is the priority.

Kigami (Yellow Paper Steel): The entry-level carbon steel from Hitachi Metals. Less pure than Shirogami, with slightly more phosphorus and sulfur content. Found in affordable, practice-grade wa-bocho. A perfectly functional steel that won't match the refinement of white or blue paper grades.

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Caring for Your Steel: Maintenance by Type

Carbon Steel (Shirogami and Aogami)

1. Dry immediately after every wash — don't let water sit on the blade for even a few minutes
2. Wipe between cuts when working with acidic foods (citrus, tomatoes, onions)
3. Apply a thin coat of camellia oil (tsubaki abura) before storing, especially in humid environments
4. Store in a knife guard, magnetic strip, or wooden saya — never loose in a drawer where edges can contact other metal
5. Embrace the patina — the dark oxidation layer that develops on carbon steel over time actually protects the blade and is considered desirable by most Japanese knife users

Stainless Steel (VG-10)

1. Hand wash and dry — dishwashers are technically possible but will dull the edge faster due to vibration and harsh detergents
2. No oil needed for normal use — the chromium content handles corrosion protection
3. Sharpen less frequently than carbon steel, but don't neglect it — VG-10 still needs periodic maintenance on a 1000-grit whetstone
4. Avoid cutting on glass, ceramic, or stone surfaces — these destroy any knife edge, regardless of steel type
5. Use a wooden or soft plastic cutting board — end-grain wood is ideal for preserving edge life

Use our steel comparison tool to find the right maintenance level for your kitchen habits.

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Frequently Asked Questions

Is Aogami Super the "best" Japanese knife steel?

It depends entirely on what you mean by "best." Aogami Super achieves the highest hardness (HRC 67) and longest edge retention of any carbon steel in the Hitachi lineup. But it's also the hardest to sharpen, the most expensive, and offers zero rust resistance. For a professional sushi chef who sharpens daily and values edge longevity above all else, it might be ideal. For a home cook who doesn't want to worry about maintenance, VG-10 is objectively a better choice. "Best" always means "best for your specific needs and habits."

Can I use a Shirogami knife if I'm a beginner?

You can, but be honest with yourself about maintenance commitment. Shirogami rewards good habits and punishes neglect. If you're willing to dry your knife immediately after every use and learn basic whetstone technique, a Shirogami knife will teach you more about edges and sharpening than any stainless blade. If you know you'll occasionally leave knives in the sink, start with VG-10 and upgrade to carbon steel later.

Why is VG-10 so popular in exported Japanese knives?

Three reasons. First, corrosion resistance — international customers (especially in humid climates) are less accustomed to the careful maintenance that carbon steel demands. Second, VG-10's balanced properties make it a "safe" recommendation that won't disappoint any user. Third, VG-10 is relatively economical to manufacture into the Damascus-clad knives that international buyers find visually appealing. The stainless core bonds well with the decorative outer layers.

What's the difference between Shirogami #1 and #2?

The main difference is carbon content: #1 has 1.25–1.35% carbon versus #2's 1.05–1.15%. Higher carbon means higher achievable hardness (HRC 66 vs. 63–65), which translates to longer edge retention. But it also means #1 is more brittle, harder to sharpen, and more demanding of the smith's heat treatment skill. Shirogami #2 is the industry standard because it offers the best balance — #1 is for users who specifically want maximum hardness and are willing to accept the trade-offs.

Do Japanese chefs actually care about steel type when buying knives?

Absolutely. In Japanese professional culinary circles, steel type is one of the first specifications discussed when selecting a new knife — often before discussing brand, handle style, or even blade shape. The Jikko Cutlery website dedicates extensive educational pages to helping chefs understand steel properties, and knife shops in Kappabashi and Sakai organize their inventory by steel type as a primary category. Our maker database lets you filter by steel type to find knives in your preferred material.

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Related Reading

• Sakai vs. Seki vs. Echizen: Japan's Three Knife-Making Capitals Compared
• How to Sharpen a Japanese Knife: The Whetstone Method from Japanese Masters
• The 10 Best Japanese Knives on Kakaku.com: Translated Rankings and Reviews

— The Blade & Steel Team