If you are in the market for a new knife, the chances are you have come across a variety of blades containing different materials. While each blade will offer the same basic abilities with cutting and hacking in the short term, each brings with it own set of advantages and caveats which are essential to consider when making a decision as to which knife to invest in.
Making sure that you select a Steel that will fit your specific purpose will ensure that you get the most out of your knife. Also, knowing the properties of different types of Steel is absolutely essential to ensuring the tool’s proper upkeep and preparation. In order to get the most value from your knife, it is important to have an understanding of how Steels and other materials differ from one another, as it will enable you to pick the correct blade for the job at hand as well as enable you to look after it properly.
What Makes Steel Different?
Steel blades differ based on the combination of various different ingredients used to comprise the blade. Each of these ingredients adds something to the blade, and Steel types are combinations which vary the levels of these elements.
The common elements found in knife Steel are these: Chromium, Carbon, Manganese, Copper, Cobalt, Molybdenum, Nickel, Nitrogen, Sulfur, Silicon, Phosphorus, Tungsten, and Vanadium. Differing the present levels of each of these elements in the Steel used will give you a different type of Steel that embodies the different properties of these elements.
The Properties Of The Elements
Chromium is mixed into Steel to combat corrosion and is found mostly in Stainless Steel knives as a major ingredient. While it is an essential component, too much Chromium can decrease the toughness of the blade. Copper is also used to combat corrosion.
Carbon is used to harden the Steel, increasing the blade’s lifespan. Having high Carbon levels present in your blade’s Steel will generally ensure that the blade wears less over time, however, just as with Chromium overly, high levels can decrease blade toughness.
Manganese, much like Carbon, is used to harden the Steel but can increase brittleness if used in too high a quantity. Tungsten and Vanadium are also used to increase the wear resistance of the Steel, and so these are the elements to look for in a knife that you need to last a long time.
The levels of Phosphorus, Cobalt, and Silicon present will dictate the blade’s strength, while Molybdenum acts to maintain this strength even at higher temperatures.
Knife blade Steel is a fine science which requires precise mixing. By using this breakdown of elements as a guide, you can make an informed decision when looking at the different mixes of Steel available to you to make sure that the blade you select is fit to your specific purposes.
The Different Types Of Knife Blade Steel
One of the main discussions usually found around knife blade Steel is Stainless Steel vs Carbon Steel, however, this is relatively misleading as it leads to the assumption that these are the only two options available on the market. In truth, there are many more varieties of knife blades available, though Stainless and Carbon Steel do make up the majority of commercially available knives.
Stainless Steel knives are probably the most common household name when it comes to knife blades, as the majority of kitchen knives are made of Stainless Steel. Stainless Steel knives are highly desirable to many due to their rust resistance, which is a factor brought about by their high levels of Chromium. This is the material from which some of the best bushcraft knives are made of.
Of course, there are many different subsets of Stainless Steel blades which contain varying degrees of different elements. Two notable examples of Stainless Steel blades are the 400 series and the AUS series. The 400 series ranges from 420 Steel – which is a low-end Steel with poor hardness and edge retention but exceptional rust resistance even from salt water – to the 440 Steels – which offer varying degrees of rust resistance and hardness.
The Japanese AUS series makes use of Vanadium to improve the wear resistance of the Steel and improve toughness. Importantly, it also makes the blade easier to sharpen.
Pros and Cons:
- Stainless Steel is exceptionally useful in situations that require rust resistance
- Typically poorer at retaining an edge and much harder to sharpen than other materials.
Carbon Steel knives are usually denoted by numbers marking their Carbon content. The 10XX series ranges from 1045 to 1095, with the last two numbers measuring the Carbon percentage (1045 containing 0.45% Carbon and 1095 containing 0.95% Carbon). While the Carbon content increases with the numbers in the series, the Manganese decreases, which in essence means that blades higher up in the series are more wear resistant but less tough, and while the lower end of the series does not hold an edge as well the higher end is much easier to sharpen and holds its edge much better.
The major drawback of Carbon Steel vs Stainless Steel is that while Carbon Steel is usually much tougher and more durable, it lacks the rust resistance of Stainless Steel, particularly higher up the series. For this reason, many of the higher end 10XX series knife blades will come with a resistant coating to ward off the rust. It is also important that these blades are stored properly to protect them.
Pros and Cons:
- Incredibly tough and resistant, holds an edge impressively
- Not rust resistant requires much more maintenance than Stainless Steel
Tool Steels are Steels specifically designed and tailored to perform certain tasks. A notable example is A2 Steel, which is extremely tough and often used to make combat knives. The downsides to this Steel is its poor wear resistance and its propensity to rust due to low Chromium content. Some other examples of tool Steel are M2 Steel – very heat resistant and holds an edge well, but brittle at larger sizes – O1 and O6 Steel – extraordinarily good edge retention, but quick to rust due to high carbon content – and W2 Steel – an ultra-hard steel with great edge retention.
Pros and Cons
- Very good at meeting specific requirements for specialized jobs
- Expensive and tends not to cater to the general market
Alloy Steels are Steels that are comprised of element combinations which mean that they do not fall into either Stainless or Carbon Steel classifications. Perhaps the best example of this is 5160 Steel, which is 1060 Carbon Steel (0.60% Carbon) mixed with a small amount of Chromium. Though there is insufficient Chromium present to be truly rust-resistant, there is enough to make the blade especially strong and tough. These Steels are perfectly fine for most jobs, but – like tool Steels – are usually specifically rendered for a specific purpose that sits outside that of a common all-purpose knife.
Titanium blades are very lightweight, flexible and tough. Problematically, these blades do not hold their edges well and tend to only be used for diving, vanity pieces, and custom knives.
Ceramic blades are very brittle blades which offer exceptional hardness and edge retention, as well as having no Steel in them to rust. While this does mean that they are incredibly easy to keep, it also means that they are far less flexible than the majority of other materials available. This makes them perfect as diving knives, but a lot less useful in other situations.
Pros and Cons:
- Extraordinarily tough and great edge retention, easy to maintain
- Inflexible and limited in its use
What Factors Should You Consider When Comparing Different Knife Blade Steels?
Of course, knowing about the makeup of different types of knife blade Steel is just one part of the equation when it comes to making a decision about which blade to choose. In addition to this, you have to consider the work that you are planning to use the blade for, the storage facilities you have available, the conditions in which you will be using it, and – importantly – your own abilities knife care and maintenance.
For example, buying a Stainless Steel knife is perfect for the user who wants to get the most out of their knife without needing to worry as much about the upkeep and protection of the blade, and makes an ideal companion for damp or waterlogged situations such as camping and cooking. However, if your task requires a blade that will retain its edge for a longer period of time – such as survival situations – then Carbon Steel knives are likely much more fit for purpose.
The caveat of Carbon Steel compared to Stainless Steel is that it requires much more maintenance and protection due to its lack of rust resistance. This means that if you are unsure of your own abilities with maintaining blades or lack the proper tools and storage facilities for such a blade, you are safer falling back on a Stainless Steel blade.
Of course, as noted above, Stainless Steel and Carbon Steel are not the only options available on the market. However, they are certainly the most widely applicable options. Alloy Steels and Tool Steels are highly specialized to their purposes and do not have the flexibility offered by Stainless Steel and Carbon Steel.
Ceramic blades, similarly, are really fit to one specific purpose rather than a broad range of different purposes. For an all-purpose knife such as a survival knife, therefore, these materials are rather less than ideal.
The variety of Steels available for common knife blades is great, and there are a number of different combinations to suit specific needs and more general needs. Having an understanding of these tools should help you to make a properly informed decision and ensure that you get the right tool for what you are doing.