What Is AUS-10 Steel? Everything You Need to Know
If you've researched premium Japanese knives, you've probably come across the term AUS-10 steel. But what is AUS-10 really — and why is it such a strong choice for high-performance kitchen knives? Let's break it down.
AUS-10: a quick definition
AUS-10 is a Japanese high-carbon stainless steel developed by Aichi Steel (Aichi Techno-Metal Co.), one of Japan's most respected steel producers. It belongs to the AUS series (AUS-6, AUS-8, AUS-10), where the number reflects the carbon content — AUS-10 sits at the top, engineered to balance sharpness, edge retention, and corrosion resistance.
What's inside AUS-10? (The composition)
AUS-10's performance comes from a carefully balanced recipe:
- ~1% carbon (0.95–1.10%) — for hardness and edge retention
- ~13–14.5% chromium — for stain and corrosion resistance
- Vanadium (0.10–0.27%) — for a fine grain structure and a keener, more durable edge
- Molybdenum (0.10–0.30%) — for strength and toughness
- Nickel & manganese (~0.5% each) — for resilience and ease of production
It's often compared to VG-10: the two are close in carbon content, but AUS-10 typically carries slightly less chromium and is widely regarded as tougher and a little easier to sharpen, while offering outstanding value.
How hard is AUS-10 steel?
AUS-10 is typically hardened to 58–61 on the Rockwell scale (HRC) — significantly harder than a typical Western knife (usually 54–56 HRC). This higher hardness is exactly why AUS-10 knives take such an acute, razor-sharp edge and hold it far longer.
The benefits of AUS-10 steel
- ✅ Outstanding edge retention — stays sharper, longer
- ✅ Excellent corrosion resistance — the chromium content fights rust
- ✅ Takes a razor edge — fine grain sharpens beautifully
- ✅ Tough and forgiving — a little easier to sharpen and maintain than some harder steels
How Oni Craft uses AUS-10: san-mai construction
Every Oni Craft blade features a high-carbon AUS-10 cutting core protected by two outer layers of 430 stainless steel. This three-layer "san-mai" construction is the best of both worlds: the hard AUS-10 core holds a razor edge, while the softer stainless cladding adds toughness, corrosion resistance, and that beautiful layered look.
One thing to know
Because AUS-10 is hard, it should be cared for accordingly: hand wash and dry it, use a wooden or plastic cutting board, and sharpen on a whetstone rather than a coarse honing steel. Learn how to care for your Japanese knife here. Treated well, an AUS-10 blade lasts a lifetime.
Why Oni Craft uses AUS-10
Every Oni Craft knife is handmade with an AUS-10 Japanese steel core — because we believe you deserve a blade that performs at the highest level for decades. That's also why each one comes with our lifetime guarantee.
👉 Discover our handmade AUS-10 Japanese knives.