440A Steel : Full Details and Review

What is 440A Steel?

440A is a 400 series Martensitic stainless steel with Carbon and Chromium content of 0.7% and 17% respectively. The high levels of Chromium give it excellent corrosion resistance, while Carbon is one of the major factors that gives the steel its characteristic hardness.

The steel has several other elements which combine together to improve the alloy’s hardness, machinability, and other properties. This makes it a common material in production of cutlery, knives, scissors, surgical tools, etc.

Being a relatively affordable steel, 440A is also used in the manufacture of replica weapons.

Though slightly inferior to higher grade 440 steels, it does offer amazing benefits for its cost. These include;

• High corrosion resistance
• Great machinability
• Decent edge retention
• Low production costs
• Easily available for all manufacturers

440A Composition

The chemical composition of steel impacts its properties and consequently its strength and functionality. 

440A steel contains 0.7% Carbon and 17% Chromium. Carbon elements are the major factor determining its hardness as well as wear resistance. Chromium, on the other hand, mainly increases corrosion resistance. The full chemical composition of 440A steel is as follows;

• 0.7% Carbon 
• 17% Chromium 
• 1% Manganese 
• 0.03% Sulfur 
• 0.75% Molybdenum 
• 1% Silicon 
• 0.5% Nickel 
• 0.04% Phosphorus

Edge Retention

Several factors determine the edge retention of steel, such as the type and amount of carbides as well as the edge profile and sharpening angles.  Without delving too far into those details in this article let's keep it simple.

For great edge retention, there should be high amounts of Carbon to boost hardness. The amount of Sulphur and Phosphorus should be  moderate to reduce brittleness.

440A steel has decent amounts of Carbon, which can raise its hardness to 55-58 HRC when properly heat-treated. This gives the steel considerable edge retention. However, it’s not comparable to higher 440 steel grades (440B and 440C), which contain higher amounts of Carbon.

Hardness

440A is a fairly hard steel. It contains 0.7% Carbon, which helps raise its hardness to 55-58 HRC when properly heat-treated.   

Toughness

The steel contains 1% Manganese and 0.5% Nickel which help improve its tensile strength. Overall, it does hold up against lateral pressure relatively well compared to some harder, superior steel grades.

Corrosion Resistance

Perhaps, the highlight of 440A steel is its great corrosion resistance. The high levels of Chromium help protect the steel from damage caused by external elements.  

This makes it a great material for outdoor knives as it does hold pretty well under extreme external elements. 

Sharpening

The Hardness or softness of a blade largely determines its ease to sharpening.  Other factors such as the type, amount, and grain size of extremely hard particles called carbides, (Cementite, Vanadium carbide, Chromium Carbide, etc.)

With a Rockwell hardness of 55-58 HRC, 440A is a relatively soft blade steel compared to 440B or 440C. This, along with the exclusion of other carbide forming elements, makes it fairly easy to sharpen.

440A Equivalent Steels

440A is almost identical to 440B with the difference being the content of Carbon in the two grades. While the Carbon content in 440A is 0.7%, in 440B, it ranges between 0.75-0.95%.

AUS-6 is also comparable to 440A. The two steels contain the same amounts of Nickel, Manganese, Silicon, Sulphur and Phosphorus. Slight variations appear only in their Carbon and Chromium elements.

Is 440A Steel a Good Knife Steel?

Carbon content is one of the major contributing factors that boost a steel’s wear resistance hence its durability. Though 440A has moderate Carbon content, it is a fairly durable steel compared to some other lower-end blade steel. 

Nevertheless, the corrosion resistance of 440A steel makes it a good knife blade. Its balanced properties make it a favorite among manufacturers of budget conscious outdoor, kitchen, and EDC knives.  A slight upgrade to 440A that is available in a wide variety of knives is 8cr13MoV blade steel.

Rough Rider Titanium Series Canoe Black Bone

The Rough Rider is a classic two blade folding pocket knife that reminds me a lot of the knife my grandpa used to carry every day.  This is the type of knife that would make a great gift for anyone who wants a classic and extremely usefull pocket knife.

Made with 440A steel it is easy to sharpen and able to hold up to most every day knife uses.

If you’re looking for a knife with excellent edge retention and wear resistance blade, 440A isn’t the right steel for you. 440C or other superior steels would be more ideal.

However, if affordability, ease of sharpening, and corrosion resistance are your concerns, then a 440A steel blade is worth your consideration. Whether you want a hunting, camping, or an EDC knife, 440A steel blades support all these uses. 

The examples we have mentioned above represent a sea of knives with a 440A steel blade. There are many others in the market with unique designs, size, and finishing. In addition, you can find a 440A steel blade no matter your budget.