So, what is 440A stainless steel?
440A is a high carbon stainless steel in the 440 family steel. You can easily find other 440 steel that are 440B, 440C, and the less common 440F.
All its in the 440 series are famous for their true stainlessness, but our main character today, 440A, is the highest corrosion-resistant one.
It is often used in the knife industry to make blades, cutting devices, and knives because the highlight feature of this type is the corrosion resistance and wear resistance.
440A gains the love of customers for its perfect combination of corrosion resistance and toughness.
To understand it clearly, you should first answer the question of the chemical composition of it. So, what are the strengths and other features of 440A that come from?
- CARBON – 0.75%: Carbon is added to increase the hardness and corrosion properties of it. However, the high amount of it will deteriorate the strength. 440A has the least amount of carbon in the 440 series of steel. Therefore, it is the highest stainless.
- CHROMIUM – 18%: Chromium helps to enhance tensile strength. The key function of this element is that it improves the edge reliability of the edge. Besides, chromium is corrosion-resistant and water-resistant.
- NICKEL – 0.6%: Boost the toughness
- MANGANESE 0.75%: Improve the hardness; the high amount of it will increase brittleness.
- SILICON – 0.1% : For hardness and strength.
- PHOSPHORUS – 0.04%: Improve hardness and strength like Silicon.
- SULFUR – 0.03%: This element will improve the machinability of it. However, it will also decrease the strength.
- MOLYBDENUM – 0.09%: Similar to Sulfur, Molybdenum is added to increase the machinability of steel. Besides, it also helps to boost strength.
How is it made?
The first step is to anneal it. In this stage, it is heated at 850-900 degrees C. Then, it is slowly cooled to 600 degrees C in the furnace.
Next, it is hardened by increasing the temperature to 1010-1065 degrees celsius; warmed oil is used to quench the hot steel. After the hardening, it is tempered at 150-370 degrees C. Lower temperature makes it harder.
Hardness: The number one factor when evaluating one steel is hardness. With 440A, the hardness fluctuates between 55 HRC and 58 HRC.
Edge Retention: With a high hardness up to 58 HRC, it has good edge retention that can handle hard substances.
Ease of sharpness: In spite of hard and stainless steel, sharpening the blades is quite easy.
Corrosion resistance: With 18% Chromium in it, it has a higher rate than other types of steel. That’s why 440 is among the best corrosion-resistant steel.
Wear Resistance: 440A composition is 40% Carbon, which gives it also good wear resistance but not the best. This amount is enough for normal use, such as camping, outdoor, and kitchen use.
Machinability: Speaking of machinability, all 440 sheets of steel are easy to process.
Toughness: Due to a high rate of Nickel and Chromium, it has quite good toughness. However, it is not the best, just at an acceptable level for mid-end steel.
Can it be used for making knives?
Absolutely yes. It is perfect to manufacture knives. With the great corrosion resistance and hardness up to 58HRC, it is excellent for kitchen knives. Besides, it can be used to make camping knives.
The downside is that it is not suitable for harsh usage with high intensity as cheap steel. Because the wear corrosion is not good, it is not perfect to be a hunting blade.
Great knives made of it
This is a pocket knife made of steel 440A from the brand Puma. As you can see in the picture, the knife has an eye-catching, sleek design, and a hole runs along with the knife. Made from 440A steel that is extremely corrosion-resistant, the knife is perfect for outdoor activities like camping.
Another highlight of this knife is that the handle made from ABS is extremely attractive.
Located in the same low-end segment, with the same low prices of the same chemical components, the 420HC and 425M have characteristics most closely resembling the 440A.
We use a scale from one to ten to evaluate four factors: Toughness, corrosion resistance, sharpness, edge retention.
420HC has corrosion resistance and hardness equal to 440A at 6 points.
In terms of edge retention, both have low edge retention. In detail, 440A is at 1/10 low, losing 1 point for 420HC. In contrast, the ease of sharpness of 440A is close to the highest point (9/10), 2 points higher than 420Hc.
440c steel has much better edge retention than 440A (2.5 / 10). However, it’s quite hard to sharpen at the level 7/10 when compared to 440A 6/10.
Both have approximately the same hardness and corrosion resistance.
In A Nutshell
To sum up, through our 440A stainless steel review, you can see that 440A is low-end steel with the perfect corrosion resistance. It can be used to manufacture knives that could be used both indoor and outdoor. Although the edge retention is low, it is completely acceptable for the price.
Thank you for your time!
Last Updated on March 31, 2021 by Andy Wang