White steel, known in Japanese as Shirogami, is a high-carbon steel produced by Hitachi Metals in Yasugi, Japan. It’s one of the most respected blade steels in Japanese knife-making, prized for its purity, its ability to take an extraordinarily sharp edge, and its predictable response to traditional forging techniques. The name comes from the white paper wrapping used to label the steel at the factory, distinguishing it from blue steel (Aogami), which gets a blue paper label.
Hitachi produces white steel using high-quality iron sand and smelting methods closely related to those used for traditional Japanese sword steel. The result is an almost pure carbon steel with very few impurities or added alloy elements, which gives it properties that blacksmiths and chefs have valued for generations.
What Makes White Steel Different
White steel’s defining characteristic is its simplicity. It contains carbon, a small amount of manganese (0.20 to 0.30%), and almost nothing else. Phosphorus sits at just 0.03%, and sulfur at a remarkably low 0.004%. There’s no tungsten, no chromium, no vanadium. This clean composition is exactly the point: fewer alloying elements mean the steel responds predictably to heat treatment, and the fine-grained structure allows a blade to reach an exceptionally thin, keen edge.
By contrast, blue steel (Aogami) adds small amounts of tungsten and chromium to improve edge retention and durability. Those additions make blue steel tougher and longer-lasting, but they also make it harder to sharpen and slightly less capable of reaching the same razor-fine edge. White steel trades durability for purity and precision.
Grades of White Steel
White steel comes in numbered grades, with #1 and #2 being the most common in knife-making. The primary difference between them is carbon content, which directly affects hardness, sharpness, and brittleness.
- White Steel #1 (Shirogami #1) contains 1.25 to 1.35% carbon. This is the higher-carbon version, capable of reaching 63 to 65 on the Rockwell Hardness scale (HRC) with proper heat treatment, and some sources cite a maximum around HRC 66. It produces the sharpest possible edge but is more brittle and less forgiving of lateral stress or improper technique.
- White Steel #2 (Shirogami #2) contains 1.0 to 1.15% carbon. It’s slightly softer, slightly tougher, and easier to maintain. Most professional chefs who use white steel knives daily reach for #2 because it strikes a practical balance between sharpness and resilience.
The higher the carbon content, the better a knife holds its edge, but the trade-off is real. A #1 blade can chip if it hits bone or is twisted during a cut, while a #2 blade absorbs that kind of stress more gracefully.
How White Steel Performs in the Kitchen
White steel is the traditional choice for Japanese knives that demand surgical precision. Yanagiba (sashimi knives), usuba (vegetable knives), and high-end gyuto (chef’s knives) are commonly forged from it. Sushi chefs in particular favor white steel because the clean, smooth cuts it produces affect the texture and appearance of raw fish. A white steel blade, sharpened properly, can slice through a piece of tuna with almost no resistance.
Honyaki knives, which are forged from a single piece of steel using traditional sword-making methods, are often made with Shirogami #1. These are considered some of the finest kitchen knives in the world, and they require significant skill both to make and to use.
Compared to stainless steels or high-alloy tool steels, white steel doesn’t hold its edge as long. Steels with vanadium or other hard carbide-forming elements will stay sharp through more cuts before needing attention. But white steel is dramatically easier to sharpen. Where a high-alloy blade might require extended time on a stone, a white steel knife comes back to a razor edge quickly and with less effort. For professional cooks who sharpen daily, that ease of maintenance matters more than maximum edge retention.
Sharpening White Steel
White steel is often called the gold standard for sharpening because it responds so well to whetstones. The fine, uniform grain structure means the steel removes evenly, and you can feel the edge developing as you work. A 1000-grit whetstone will restore a dull white steel blade to good working condition. For refining and polishing the edge further, grits of 3000 to 6000 bring out the steel’s full potential. If the blade is chipped or heavily damaged, starting below 1000 grit will remove material faster.
Many knife enthusiasts find sharpening white steel genuinely enjoyable. The feedback through the stone is immediate and consistent, which makes it an excellent steel for learning freehand sharpening technique.
Rust and Maintenance
White steel’s biggest practical drawback is that it rusts. With no chromium in its composition, it’s fully reactive. Moisture, acidic foods, and even the humidity in a kitchen can cause oxidation if the blade isn’t cared for. A patina (a thin, dark layer of stable oxidation) will develop naturally with use, and many cooks welcome this because it actually slows further corrosion. But active rust, the orange, pitting kind, will damage the edge and the steel beneath it.
Keeping a white steel knife in good condition is straightforward but non-negotiable. Wipe the blade dry after every use. Don’t leave it sitting in a sink or on a wet cutting board. After your session, a thin coat of food-safe oil (camellia oil is traditional in Japan) protects the steel during storage. Store the knife in a dry spot with good airflow, not in a closed drawer where moisture can collect.
If you’re used to stainless steel knives that you can toss in a dish rack without a second thought, white steel will feel high-maintenance at first. But the routine becomes automatic quickly, and the cutting performance it delivers is the reward.
White Steel vs. Blue Steel
This is the comparison most people are weighing when they research white steel. Both are Hitachi Yasugi products, both are high-carbon, and both are used in premium Japanese knives. The core difference is that blue steel contains tungsten and chromium, which white steel lacks entirely.
Those additions give blue steel better edge retention and slightly more resistance to chipping. A blue steel knife will stay sharp longer between sharpenings. But white steel takes a finer edge, sharpens more easily, and offers a “purer” cutting feel that many traditional chefs prefer. White steel is also more responsive to heat treatment, which gives skilled blacksmiths more control during forging.
Neither is objectively better. White steel suits cooks who sharpen frequently and want the absolute sharpest edge possible. Blue steel suits cooks who want durability and longer intervals between sharpening sessions. Professional sushi chefs tend to lean toward white steel. Line cooks working long shifts with varied ingredients often prefer blue.