Knives can be one of the most useful tools at your disposal, whether it is in a kitchen setting or in the great outdoors, but like all tools, a knife is only as useful as it is capable. In other words, if it is made out of inferior materials, it might not be much use to you.
440 steel is one of the more common materials used in manufacturing knife steel, and it has found itself in this position thanks to its well-blended mix of hardness and rust-resistance, which makes it very well suited to use as a knife blade.
440 steel, in general, is great knife steel, but there are actually different grades that boast different qualities. Likely due to marketing reasons, these differing grades are rarely advertised, with “440,” usually being the only thing that gets stamped on the blade or printed on the box.
What Are the Different Grades of 440 Steel?
So, the natural question to ask next is, what are those different grades of 440 steel, and what is the difference between them? There are three different grades of 440 steel, each identified by a letter after the number. 440A, 440B, and 440C.
440A Grade Steel
440A steel is a low-cost option when it comes to 440 steel. This is because it is the softest of the different 440 grades—which is not to say it is a soft metal; it is just softer than 440B and 440C. It is also the most resistant to rust of the different grades. These attributes make it particularly well suited for use in environments like kitchens, where the rigors it will be put through are not as harsh as some other knife uses, but it will be exposed to a lot of moisture.
440B Grade Steel
There are no unexpected twists to the way these grades play out. 440A is the softest and most rust-resistant of the 440 steel grades, whereas 440B falls somewhere in the middle of A and C. You can expect better edge retention from this grade at the expense of slightly less rust-resistance, though it should be noted that this does not mean 440B will rust easily.
440C Grade Steel
The toughest, most durable of the 440 steel grades also has the worst rust-resistance. That being said, once again, we are not saying that it will rust easily, just that it has less rust resistance than the other 440 grades.
We mentioned that the true grades rarely make it onto the marketing material, which, while a little dishonest, is par for the course in the world of sales. Knife manufacturers will often put the 440 number on their blades but leave off the actual grade so that people who are looking for a particular grade may buy that particular model, even if it is not the grade they are looking for.
As a general rule, 440C is considered to be the highest quality of the 440 steel grades, so if a knife is not explicitly labeled as “440C”, it will almost certainly be one of the two lower grades since the manufacturer would be keen to make a point of their knife using 440C if that were the case.
The sometimes insincere marketing tactics of knife manufacturers can, understandably, make people wary of buying their products, but when it comes to 440 steel, all the various grades are perfectly suitable for use in knives. For knives that are going to be facing a lot of abuse, you may want to go out of your way to ensure you get a 440C blade, as that this will provide more edge retention and stand up to blunting and chipping more readily.
It is also worth noting that there are other “400” steels that are sometimes found in knives, such as 420 and 425M. While these metals are suitable for use in knives to some degree, they are far from the quality that you get with 440 steel. So when we say that all of the different grades of 440 steel are excellent for knife blades, we are only referring to the 440A, 440B, and 440C variants, not any of the grades that start with something other than “440”.