O1 Tool Steel Guide

10 Best Utility Knives Video
10 Best Utility Knives Video

O1 tool steel is a cold work steel and is one of the most forgiving for making knife blades. It’s known as a low alloy steel due to the fact that it contains eight additives.  The largest additive is Manganese at just 1.2%. The other minerals added are Carbon at 0.95%, Silicon at 0.4%, Chromium at 0.5%, Tungsten at 0.5%, Vanadium at 0.2%, Phosphorus at 0.3%, and Sulfur at 0.03%. In reference to the listed additives, O1 steel is in compliance with SAE J437 and J438, ASTM A681, and DIN 1.2510.

Chemical Composition

O1 tool steel is a cold work steel and is one of the most forgiving for making knife blades. It’s known as low alloy steel due to the fact that it contains eight additives. 

Element%
Carbon0.95
Silicon0.4
Chromium0.5
Tungsten0.5
Vanadium0.2
Phosphorus0.3
Sulfur0.03

 In reference to the listed additives, O1 steel is in compliance with SAE J437 and J438, ASTM A681, and DIN 1.2510.

O1 Tool Steel Properties

Hardness

O1 tool steel specification and instructions specify that this steel hardens and tempers to a Rockwell hardness of 57-58HRC. This is a considerably high hardness level and provides a perfect balance between toughness, wear resistance, and great edge retention.

You do not have to worry about the surface of your O1 steel getting destroyed or chipped away easily.

Toughness

A tough steel blade resists chipping and complete breakdown when subjected to impact, beating, twisting, and torsion. Tough blades are perfect for camping and outdoor use in the wild. Where a normal steel blade might chip or even break down, tougher steel blades are able to withstand that and much more such as batoning sessions, steel strapping, and much more!

The O1 tool makes considerably tough knives. The O1’s steel chipping resistance is quite high compared to other steel knives which have the same Rockwell hardness. The steel provides high toughness levels for knife-making.

Some people might argue that the O1 steel is not the toughest steel available, but we cannot ignore that that it manages to provide a decent amount of toughness for knives while at the same time maintaining high hardness, wear resistance, and grindability.

You can put your full trust in your O1 steel knife to last a good period of time with decent maintenance and without showing any signs of chipping or cracking under stress.

Edge retention

The edge retention is the knife’s ability to hold its sharpness while in use. Whether it is cutting up nylon ropes, cutting fresh meat, sharpening wood, or cutting up cardboard boxes, no one wants to deal with a dull knife. The performance you can observe during cut tests is quite remarkable when you compare high-end steels to lower-end ones.

Edge retention and hardness typically go hand in hand. The O1 steel is mainly used for cutting other knives and blades which means that it delivers decent edge retention.

After sharpening your O1 knife steel, you can be sure as hell that it will retain its sharpness for a really long period of time. This is a great factor as this will lead you to decrease the frequency of sharpening your steel, and subsequently, preserve the steel’s quality.

Corrosion resistance

Are you someone who tends to venture out into the wild, salty, wet, and humid environments? Do you often use your knife for prepping meals with acidic ingredients such as tomatoes or lemon? 

Certain steels are pretty good at resisting rust and corrosion and can be left uncleaned for hours without any complications or ill effects. Carbon steel knives will easily pit and rust in wet, humid environments if not looked after properly. Usually, knives with a low corrosion resistance can be protected with a thin layer of mineral oil.

As we already know, Chromium is the essential factor for controlling corrosion resistance in a steel alloy, besides additional chemical elements like Nitrogen and Molybdenum. Keeping that in mind, the amount of Chromium is quite low – as much as 0.6% – which results in overall average corrosion resistance. 

Ease of sharpening

Usually, the most overlooked aspect of blade steel is its sharpenability and sharpness. Touching up or sharpening certain steels with a sharpening stone can be quite a simple, easy, and relaxing process whereas harder steels can make the process much tougher, tedious, and not so relaxing. 

Achieving the right amount of sharpness can be a life-or-death matter when you are out in the wild, as it determines your ability to cut up and cook food as well as other tasks. It is crucial to keep in mind that an easy to sharpen knife usually indicates low edge retention.

For steel that exhibits such sort of hardness and wears resistance, one would expect it to be equally hard to sharpen. But surprisingly, O1 steel is quite easy to sharpen and does not require you to break your back over it.

Heat Treatment of O1 Tool Steel

Annealing

Strengthening should be performed after hot working and before re-solidifying. 

Warmth at a rate not surpassing 222°C each hour to 802-816°C, and hold at temperature for 1 hour for every inch (25.4mm) of most extreme thickness; 2 hours least. Then, at that point cool gradually with the heater at a rate not surpassing 28°C per hourto 538°C. Keep cooling to surrounding temperature in the heater or in air. The resultant hardness ought to be a limit of 212 HBW. 

Stress Relief of Unhardened Material 

Heat it up gradually to 1250° F. Splash for two hours for every inch of thickness at heat. Moderate cool (heater cool if conceivable) to room temperature. 

Solidifying 

Preheat: Heat marginally prior to dashing into the preheated furnace which ought to be working at about 1100°-1200°F. 

Solidifying: Heat to 1475 to 1500° F. Douse at heat for 30 minutes for each inch of thickness. 

Extinguish: Quench O1 steel in warm oil and permit to cool in the oil until a temperature of 125°-150°F has been reached, or to where the part can be held in the exposed hand, and temper right away. 

Temper: Normally oil solidifying preparations should be single tempered as it were. Notwithstanding, twofold hardening some of the time may be liked. Douse at heat for 2 hours for every inch of thickness for each temper. Air cool to room temperature between tempers. The typical hardening range for this evaluation is 300 to 450° F. 

Stress Relief Temper 

A pressure alleviation temper for solidified material is firmly suggested after huge granulating, or welding, or EDM. Select a temperature that is 25 or 50° F lower than the last treating temperature utilized.

Applications for O1 Steel

O1 tool steel is used for applications requiring tough, rugged parts including punches, knock-out pins, cams, and of course, knife blades. Some old time knife makers have alleged that an expertly made blade of O1 will outperform a blade made of Damascus steel. Some balisong knives use 01 in their latches.

O1 Steel for Knives

O1 steel can be used to make knives because of how easy it is to work with. It is easy to form as well as sharpen. The steel produces a very good edge that won’t dull easily as well. However, O1 steel can rust and care should be taken to prevent rust. Drying and oiling the knife after use is usually sufficient. Some high-end mass produced knives use O1 steel.

Samurai Katana by Swords of Northshire

O1 steel vs. Other steels

O1 vs. 1095

O1 vs. 1095 steel comparison chart
PropertiesO11095
Toughness8/107/10
Edge retention6/105/10
Corrosion Resistance3/102/10
Ease of sharpening5/107/10

From the above table, it is fair to say that O1 tool steel provides improved toughness, edge retention, and corrosion resistance. 1095 steel provides improved ease of sharpening.

O1 vs. A2

O1 vs. A2 steel comparison chart
PropertiesO1A2
Toughness8/108/10
Edge retention6/106/10
Corrosion resistance3/105/10
Ease of sharpening5/104/10

From the above table, it is fair to say that the O1 tool steel provides improved ease of sharpening and the A2 steel provides improved corrosion resistance. Both the steels rank equally in terms of toughness and edge retention.

O1 vs. D2

O1 vs. D2 steel comparison chart
PropertiesO1D2
Toughness8/106/10
Edge retention6/107/10
Corrosion resistance3/104/10
Ease of sharpening5/103/10

From the above table, it is fair to say that the O1 tool steel provides improved toughness and ease of sharpening whereas the D2 steel provides improved edge retention and corrosion resistance.

O1 vs. H1

O1 vs. H1 steel comparison chart
PropertiesO1H1
Toughness8/107/10
Edge retention6/102/10
Corrosion resistance3/1010/10
Ease of sharpening5/108/10

From the above table, it is fair to say that the O1 tool steel provides improved toughness and edge retention whereas the H1 steel provides improved corrosion resistance and ease of sharpening.

Conclusion

In conclusion, O1 steel is one of the most versatile oil quenched, tool steels and makes for a tough, serviceable knife blade. Its toughness slows the machining process, and that makes it excellent for beginners as it takes longer to make a mistake. Thus they are often caught before they become irrecoverable. Also, because it’s so tough, once tempered, it holds an edge and resists wear extremely well. Read our machete review.

Save up to 50% on your new knife at BladeHQ

We have partnered with BladeHQ to offer the best deals on high-quality knives for our readers. The deals are always changing so click the button below to shop today.

Recent Posts

what is the best knife to cut meat

Best Knife to Cut Meat of 2022: Complete Reviews With Comparisons

Some of the sharpest kitchen knives in existence are meat cutting knives. That said, you can’t expect them to give their best cutting performance throughout the course of their service. If you’ve ever owned a kitchen knife for cutting meat before (and you likely have), you know they’re not built to last. Make sure to ... Read more
best ceramic knives for your kitchen

Best Ceramic Knives of 2022: Complete Reviews With Comparisons

While they aren’t a replacement for tough steel knives, ceramic knives are versatile and ideal for any kitchen. They are razor-sharp, rust-proof, and featherweight and are relatively inexpensive. If you’re shopping around for the best ceramic knives, then you have come to the right place. We reviewed 5 of the leading ceramic knife sets on ... Read more
what is a boning knife used for

What Is a Boning Knife Used For: Getting to Know This Handy Tool

Having a tool in your kitchen is essential, but the same tool becomes worthless if you don’t know how to use it effectively. Knives are the same; different types make your tasks easier only if you know what each type is best for. That’s why it’s vital to find out what is a boning knife ... Read more
best boning knife of 2022

Best Boning Knife of 2022: Complete Reviews With Comparisons

With a quality curved boning knife, you can break down fish and meat efficiently on your own and save money. In some knives, you even get the bonus of a filleting function where you can separate the meat fish from bone with relative ease. On that note, here are five of the best boning knife ... Read more
Here is the ultimate drop point vs clip point knife comparison.

Drop Point vs. Clip Point Knife: Ultimate Comparison [2022 Update]

There’s a wide array of blade shapes for you to choose from if you’re shopping for a versatile knife. That said, you must settle the drop point vs clip point debate first. These are two of the most common blade shapes today. They are also among the most used by reputable knife manufacturers. Each blade ... Read more
types of cheese knives

Cheese Knives: 13 Different Types and How To Use Them

Cheeses come in many forms, each offering a different experience for your taste buds. Naturally, you would need different types of cheese knives for different occasions. Some people might think slicing cheese is simple and that they can do it even with just a steak knife. Sadly, these basic kitchen tools won’t get the job ... Read more

Looking for something specific?

3 thoughts on “O1 Tool Steel Guide”

  1. Hi

    I’ve just completed my first knife with NEWHALL OIL HARDENING TOOL STEEL
    1.2510

    After a range of strength and durability tests I was quite satisfied and impressed with what I have created and went on to cook a steak for the last and ultimate test. It worked beautifully!

    After enjoying the steak I wiped the blade and to my horror I found black stains all over my shiny new knife.
    I know that blood is highly corrosive from hunting and the damage it causes if you leave it on your rifle so with this in mind I painted pickling compound (hydrofluoric acid).

    Now I’ve got a beautiful charcoal colored blade which is cool, but I would like to know though how to prevent this from happening as I don’t want to end up with a black knife every time I cut a steak.

    Thank you & best Regards
    Verner

    Reply
  2. Hi, apologies, I got distracted and didn’t finish my sentence after ‘hydrochloric acid’:

    Hi

    I’ve just completed my first knife with NEWHALL OIL HARDENING TOOL STEEL
    1.2510

    After a range of strength and durability tests I was quite satisfied and impressed with what I have created and went on to cook a steak for the last and ultimate test. It worked beautifully!

    After enjoying the steak I wiped the blade and to my horror I found black stains all over my shiny new knife.
    I know that blood is highly corrosive from hunting and the damage it causes if you leave it on your rifle. So with this in mind I painted pickling compound (hydrofluoric acid) on the entire blade. Now I’ve got a beautiful charcoal colored blade.

    I would like to know though how to prevent this from happening as I don’t want to end up with a black knife every time I cut a steak.

    Thank you & best Regards
    Verner

    Reply

Leave a Comment