Blade Steel

O1 - Blade Steel

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Steel Composition

carbon 0.90 %
chromium 0.50 %
vanadium 0.20 %

The O1 knife steel is a highly popular choice among knife makers due to its amenability to hand forging as well as its robust performance characteristics. Its significant carbon content allows it to deliver excellent hardness and edge-holding ability, making it a superb choice for hunting knives, kitchen knives, and outdoor survival tools. Notably, O1 knife steel is a type of oil-hardening tool steel and features non-shrinking properties.

What are the Advantages of O1?

The O1 knife steel offers high edge retention which makes it a perfect steel for heavy-duty cutting tools. Due to its beneficial properties, O1 is an excellent option for making EDC knives, camping gears, and hunting knives. The high carbon content contributes to its ability to maintain a sharp edge even after repeated use. Despite this, O1 tool steel is fairly easy to sharpen compared to other high-carbon steels.

Another great aspect about O1 knife steel is its toughness. Even when used to create thin and finely honed blades, the toughness ensures that the blade doesn't chip or break.

Disadvantages of O1 for Knives

The most notable disadvantage of the O1 knife steel is its limited corrosion resistance. This implies that knives made from this type of steel require regular maintenance to prevent rust. Users must ensure to keep the blade dry and oil it on a regular basis to prevent corrosion.

Moreover, while O1 knife steel is renowned for its edge retention, it may not hold up too well against abrasive materials. This might require frequent sharpening depending on the usage.

Steel Rating

Steels with good edge retention will stay sharp longer, reducing the need for frequent sharpening

Edge Retention

3/6 Points

Toughness is the steel's ability to absorb energy and deform without breaking


4/6 Points

Corrosion Resistance measures how well the steel can resist rust and oxidation

Corrosion Resistance

1/6 Points

Sharpenability refers to how easily a knife blade can be sharpened to its desired edge


4/6 Points

This is a relative measure based on typical market values. The actual price can vary widel


5/6 Points

A higher HRC number typically indicates a harder steel, which can hold a sharper edge


57 - 62 HRC
Please be aware that this rating should be understood as a comparative measure. It's simply a rough estimation in relation to other knife steels.

Is O1 Rust Resistant?

Given that O1 knife steel is not stainless, it does not inherently have high corrosion-resistant properties. As such, O1 knives are prone to rust if not taken care of properly. This means they should be cleaned after use and kept dry at all times. Periodic oiling can also significantly help delay the effects of oxidation on O1 knife steel.

How Hard is O1?

O1 knife steel can be heat treated to achieve a hardness rating of 57 - 62 HRC, which is quite high considering its balanced make-up. This level of hardness allows the O1 knife steel blade to maintain sharpness over a long period of time, making it suitable for no-nonsense tasks like woodworking, meat chopping, and heavy-duty utility work.

For What is O1 Recognized for?

O1 is a popular choice among knife enthusiasts and makers for its excellent balance of hardness, toughness, and workability. Known for being a top-notch hand-forging tool steel, this material offers longevity through its excellent edge retention skills. Despite lacking in corrosion resistance, it's still highly valued amongst certain sectors who prefer non-stainless, high-performance blade steels.

Similar blade steels


To conclude, O1 knife steel is an excellent option for knife makers and EDC enthusiasts who value hardiness, edge retention, and toughness in their blades. Although it lacks some corrosion resistance, with proper care and maintenance, an O1 knife can still serve as a trusty partner for a myriad of tasks. While it's not a premium steel, its performance puts it as a strong contender amongst medium-priced range blades.