Guide to Knife Steel

There’s nothing more useful, handy, versatile, and long-lasting as a knife, especially a good knife with a quality blade. The problem, though, is that all knives look the same for the untrained eye. Telling a good knife from a bad one can be almost impossible if you weren’t schooled by a knife expert or have not done some in-depth research about knives before.

The most significant factor of a knife’s quality is the type of steel it uses. Steel is an alloy that is made in several ways, so telling good steel apart from the lousy steel can be a headache-inducing experience. And for this reason, we present this article, which you can use as a quick reference guide to some of the most common steels used for making knives. In this way, you can make a better and more informed decision the next time you buy a knife.

What is steel made of?

The following lists the common elements present in steel and the properties they provide it.

1) Iron

the main component of steel.

2) Carbon

it hardens the iron, making it stronger. Each type of steel has some amount of carbon, and you can tell the quality of the blade through the amount of carbon it has. For instance:

  • Low carbon – 0.3% carbon or less.
  • Medium carbon – 0.4% to 0.7% carbon.
  • High carbon – 0.8% and above.

The higher the carbon, the tougher and more durable the blade.

3) Chromium

it is the element that makes the steel stainless. Technically, all steel can rust, but steel with a higher amount of chromium (typically around 12% to 13%) is less likely to rust.

4) Cobalt

it provides additional strength to the blade.

5) Manganese

it also provides additional hardness to the blade, but the edge will become brittle if it has too much manganese.

6) Nickel

it adds toughness to the blade.

7) Molybdenum

it helps steel to maintain strength in high temperatures.

8) Tungsten

it provides increased resistance to wear and tear.

9) Vanadium

it also provides increased resistance to wear and also makes the blade harder.

Common types of steels used for knives

Now that you know about the properties of steel, here’s the quick info about the common types of steel used for knives:

1) Carbon steel

Carbon steel is an alloy of iron and carbon. A carbon steel blade can hold its edge very well and stay sharp even after many uses. It is also relatively easy to sharpen. This type of steel blade is used for knives that are meant for rough uses, such as machetes and survival knives. The trade-off, though, is its tendency to rust due to low chromium content. The most popular in this category is 1095.

2) Tool steel

Most cutting tools have this type of steel. More popular steels in this group are D2, O1, and Crucible’s CPM series (such as CPM 3V), as well as more advanced high-speed steels such as M4.

3) Stainless steel

Stainless steel is basically carbon steel added with significant amounts of chromium, the element which prevents the blade from corrosion, discoloration, and other elements. It won’t also transfer a metallic taste to food. While chromium increases the blade’s performance, the downside to it is inferior toughness. A stainless steel blade is also difficult to sharpen and maintain an edge. The EDC knives are the most popular in this group, which also includes the 400, 154CM, AUS, VG, CTS, DSR, CrMo/MoV, Sandvik, CPM SxxV and Crucible SxxV series of steels. Note that genuine stainless steel knives have at least 13% chromium.

4) Semi-stainless steel

These are blades that do not fit in the “stainless steel” category because they do not have sufficient amounts of chromium. It is less prone to rust compared to carbon steel, but more prone to rust compared to stainless steel. The most popular of this category include the VGin series.

5) High-carbon stainless steel

High-carbon stainless steel knives have at least around 0.6% to 0.75% of carbon for hardness and at least 14% chromium for resistance to corrosion. Unlike stainless steel, high-carbon stainless is less prone to corrosion because of the significant amounts of chromium. But it still less tough compared to the carbon steel knives. Plus, it can be quite expensive. A high-carbon stainless steel knife can be easily sharpened and maintains a good edge.

Because of the continuous technological advancements, we probably have hundreds of types of steel blades. However, we have put up a list of some of the most popular steel blades, just to give you an idea about their properties and examples.

1) 440C

The 440C is the most popular type of steel blade from the 440 series. It has the highest content of carbon compared to its 440 predecessors. Once considered the high-end in knife steels, it now has been overshadowed by the newer and more improved types of steel blades that come after. However, the 440C is still a good and solid all-around steel blade. You can find this type on several mass-manufactured pocket knives. While it doesn’t excel much in stain resistance, the 440C is reasonably durable and wear-resistant.

2) CPM S110V

The CPM S110V belongs to the CPM SxxV series, which also includes (in order of quality): CPM S30V, CPM S35VN, CPM S60V, CPM S90V, and CPM S110V. The CPM S110V is the best in the order, as it has the highest corrosion resistance and a slightly better wear resistance. These attributes make this steel blade highly desirable for kitchen cutlery. However, it can be difficult for the knifemakers to work with and sharpening it can be quite a challenge.

3) CTS-XHP

The CTS-XHP is a relatively new steel blade from the CTS series, developed by US-based Carpenter Technology Corporation. It has a high carbon and chromium content, which makes this blade durable and resistant to corrosion. It is air-hardening steel, a class of steels which can be cooled down from a temperature above their transformation range and hardened by keeping it in the air or other similar gaseous mediums.

4) 154CM

The 154CM is widely considered as the upgraded version of the 440C due to the introduction of molybdenum. This element makes the 154CM superior to 440C in terms of edge holding. Despite having less chromium, the 154CM is reasonably rust-resistant. It is also relatively easy to sharpen, provided that you have the right sharpening tools for it. The 154CM is also similar to the ATS-34 steel blades.

5) ATS-34

It has been considered as the Japanese counterpart of the US-made 154CM series because both have similar characteristics and amounts of elemental properties. It is a high-quality steel that holds a great edge but is a bit less rust-resistant compared to the lower-range 440C steel blades.