440C steel is a type of stainless steel from the 440 alloy series, with 440A, and 440B as its siblings. What differentiates the different grades of the 440 alloy series is the carbon content.
Grade 440C stainless steel is the best steel in the 440 series, it has the high carbon content among the three 440s’, offering excellent hardenability, good wear resistance, and good corrosion resistance. However, the softer 440A and 440B offer better stain-resistance and are a better option for salt water applications.
440C Carbon steel is a genuine type of stainless steel because it contains more than enough amounts of chromium (18%) in its composition.
440C gained popularity as good steel in knife making around 20 years ago. It continues to be in the top list of steels making mid-range, budget, and pricey knives. It is also used in other applications including ball bearings and needle valves
With that, let us look at the properties that have enabled 440C to survive competition from modern steel options.
440C steel Chemical composition
- Carbon C 1.10%: Increases the edge retention, hardness and tensile strength. It also improves steel resistance to wear, abrasion and corrosion.
- Chromium Cr 18.00%: Chromium Increases hardness, tensile strength and toughness of the blade.
- Molybdenum Mo 0.75%: It improves machinability and hardening property.
- Manganese Mn 1.00%: Increases Hardness and brittleness.
- Phosphorus P 0.04%: Improves hardness.
- Sulphur S 0.03% : Increases machinability of steel but can reduce toughness in large amounts.
- Silicon Si 1.00% : Improves grain structure for better hardness, however like Manganese it can increase brittleness.
440C Steel properties
440C Steel Hardness
As already mentioned, 440C contains high levels of carbon, making it hard steel. However, heat treating stage is what will determine if it will achieve highest hardness and it’s characteristic high strength.
According to Rockwell Hardness, 440C carbon steel hardness falls between 58-60 HRC , the hardest in the 440 series. The high hardness in this steel is associated with the high levels of chromium and carbon in its composition. Tempering temperature should be at optimal temperature to achieve the desired maximum hardness.
440C Steel Edge retention
Steel with high hardness will always have excellent edge retention, which is true with grade 440C stainless steel. The high carbon levels in its composition contribute to the good edge holding capabilities.
If you are on the market for a knife that remains sharp for long, you will never regret going for 440C varieties.
440C Steel Toughness
It is rare to get steel, giving you both hardness and toughness. Therefore, with our 440C Stainless steel having a high HRC, its toughness is considered just okay. Though there are tougher steels out there, the toughness of 440C martensitic stainless steel is enhanced by high molybdenum in its composition.
This gives the blades of 440C stainless steel the ability to withstand tough applications even from outdoor use.
440C Steel Corrosion resistance
440C contains high levels of chromium, giving it good corrosion resistance properties. Despite the usage and climate conditions, you can be assured that your 440C blade steel knife will not experience corrosion or stain even with minimal care.
This property makes knives made from this steel an excellent option for wet environments.
Sharpening 440C Steel
Keeping in mind that 440C is hard steel, sharpening 440C blade might not be easy, especially for knife users without proper sharpening skills and tools. To compensate for the challenging sharpening task, this steel remains sharp for long, reducing the need for frequent sharpening.
440C Steel Wear resistance
Another property that keeps 440C steel on the knife-making market is its excellent wear resistance. Even after tough applications, the blades of knives made from this steel will last long without signs of wear.
440C Steel Polish finish look
Another property that will make you love knives made from 440C in their mirror-like finish. This mirror polish gives the blades a great look, and it is easy to clean.
440C stainless steel equivalent
440C vs D2
D2 steel is a premium steel with better hardness level than 440C carbon steel giving it better edge retention.
On the other hand, it is easier to sharpen 440C steel. It is better in corrosion resistance because it’s stainless steel, unlike D2 that does not contain enough chromium elements to make it stainless steel.
AUS-8 steel vs 440C
AUS 8 Steel can be consider 440C steel equivalent roughly in terms of the carbon content present. There is no significant difference when it comes to edge retention and toughness between the two. However, AUS 8 steel is easy to sharpen which can be attributed to the Vanadium present that improves its grain composition.
Is 440c good knife steel ?
With good edge retention, wear resistance, and corrosion resistance, 440C continues to be great steel for knives.
Also, since it is categorized as mid-range steel, the knives are affordable.
What’s more, the ability to attain a mirror finish is another feature that makes it attractive.
Before the invention of new technology steels, AISI 440C knife blades was an ideal choice for many. Some may argue it is not the best choice on the market today but funny enough 440C still remains a popular choice for professional cutlery steel. I believe if there was a better stainless steel to replace 440C it would have happened by now,
Knife maker and users still recognize it as an all-around knife-making steel. 440C heat treatment enables it to attain high Rockwell hardness giving it better wear resistance. Development of new types of steel has not phased out use 440 series alloy particularly 440C in Knife making. 440C bears a resemblance to tool steel as it requires great care in fabrication, a well polished 440C Knife will maintain its sharpness, finish and stay corrosion free for a long time. I believe you should give it a try in your next knife, from personal experience you will not be disappointed.