On our journey through the world of knife steels, it's not only important to focus on the steels we select, but also to understand the other prominent players in the market. One of the names that frequently comes up in discussions about quality Japanese knives is AUS-10. As steel experts at Viretta, we consider it crucial to know the entire spectrum of materials, and AUS-10 is an important and recognized alloy.

This article is our in-depth analysis of AUS-10. We will examine its origin, decipher its chemical composition, and evaluate its precise position in the hierarchy of modern knife steels—as well as draw comparisons to the steels we have chosen for our own series.

Origin and Purpose: Aichi Steel Corporation
AUS-10 is a high-carbon stainless steel from the renowned Japanese manufacturer Aichi Steel Corporation. The steel belongs to the well-known "AUS" series, with AUS-10 representing the highest-performing variant, developed as a significant upgrade over its predecessors AUS-6 and the popular AUS-8.

The goal for AUS-10 was to create a steel that could compete in the upper-mid-range segment—a steel with higher hardness and better edge retention than AUS-8, yet relatively cost-effective to produce and easy for the user to maintain.

Chemical Composition: A Formula for Versatility
AUS-10's strength lies in a balanced chemistry designed to deliver strong all-around performance:

• Carbon (approx. 0.95% – 1.10%): The high carbon level allows for high hardness and reliable edge retention.

• Chromium (approx. 13.0% – 14.5%): Ensures complete stainlessness and high corrosion resistance in daily use.

• Vanadium (approx. 0.10% – 0.25%): Forms hard carbides that increase wear resistance.

• Molybdenum (approx. 0.10% – 0.30%): Improves strength and toughness, increases fracture resistance.

• Nickel (approx. 0.49%): Supports toughness and additional corrosion resistance.

Heat Treatment and Hardness: The Right Balance
As with all high-quality steels, precise heat treatment is crucial to realize the full potential of AUS-10. Typically, the steel is hardened to about 58–61 HRC. This hardness class places it in a league with recognized steels such as 10Cr15CoMoV and VG-10, which we use in our Shojin series, although the chemical balance and resulting performance nuances are different.

AUS-10 in Practice: Properties at a Glance

• Edge Retention: Good and reliable. Thanks to the high carbon content and vanadium, AUS-10 holds its sharpness significantly longer than AUS-8, though not at the level of premium steels like SG2.

• Toughness: Despite high hardness, the steel maintains good toughness and is less prone to chipping than many other steels over 60 HRC.

• Corrosion Resistance: With up to 14.5% chromium, AUS-10 is a very reliable stainless steel that requires minimal maintenance.

• Sharpenability: AUS-10 is surprisingly easy to sharpen and responds well to standard sharpening stones, making it user-friendly.

Position in the Steel Universe: AUS-10 vs. Viretta Selection

• vs. VG-10 / 10Cr15CoMoV: AUS-10 is a direct competitor. Hardness is comparable, but VG-10 and 10Cr15CoMoV have slight advantages in edge retention thanks to higher molybdenum and unique cobalt content—small differences that are crucial for our Shojin series.

• vs. 5Cr15MoV: Here, the difference is clear. 5Cr15MoV (Classic series) offers maximum toughness and easy maintenance, while AUS-10 gains performance in hardness and edge retention, but sacrifices some robustness.

Conclusion: A Strong All-Rounder in the Market
AUS-10 is an excellent and capable knife steel. It offers a balanced combination of the most important properties and meets the needs of most chefs. It is a strong all-rounder that has earned its place in the market.

At Viretta, our mission is to select carefully. We analyze, test, and choose the steels that offer the optimal combination of properties for the intended use of a knife series. Although AUS-10 is an excellent steel, we believe that the unique chemistry of alloys like 10Cr15CoMoV and VG-10 provides the additional performance refinement we seek in our Shojin series.