While there are a mind boggling array of steels and exotic materials used in the production of knife blades, the most common will invariably fall into the three major groupings below.
Steel used in the production of knife blades falls into three prevailing classifications:
Tool steel, tool steels are a family carbon and alloy steels having distinct characteristics such as hardness, wear resistance, toughness, and resistance to softening at high temperatures. Tool steels comprise carbide-forming elements such as chromium, vanadium, molybdenum and tungsten in different combinations. Tool steel is the hardened alloy steel that’s used in cutting, pressing and extruding tools, it is also used to produce knife blades. tungsten, chromium, vanadium and molybdenum are the four major alloying elements that form carbides which give this steel strength, hardness and resistance to wear.
Carbon steel, carbon steel is a special type of steel that has a higher concentration of carbon than other types of steel. Most types of steel have a low carbon content of approximately 0.05% to 0.3%. Carbon steel by comparison has a carbon content of up to 2.5%. 2.5% carbon does not sound like much, but it introduces many key benefits that aren’t found in other knife blades. This type of steel is called carbon steel because of the varying levels of carbon in the alloy. Carbon is very very hard and as such blades that will invariably live a tough life, such as machetes use carbon steel. High level carbon steel is used in many knife blades as it holds an edge extremely well and is very easy to sharpen, the downside being the extra care involved in maintenance.
Stainless steel, stainless steel is an alloy of Iron with a minimum of 10.5% Chromium, in knife blade production this should be a minimum 14%. Chromium produces a thin layer of oxide on the surface of the steel known as the passive layer. This prevents any further corrosion of the surface. Increasing the amount of Chromium gives an increased resistance to corrosion. The term stainless steel is a bit of a misnomer as any metal will show evidence of corrosion given enough time exposed to the elements. This steel remains one of the most popular steels used in knife blade production. The addition of a minimum 14% chromium helps stainless steel resist corrosion. The downside being stainless steel doesn’t hold an edge in the same way high level carbon steel does and its a tad harder to sharpen.
The three different types of steel mentioned above when used in knife blades each exhibit differing levels of these five important elements:
Hardness is the ability to resist deforming when subject to stressing. Hardness in knife blade steel is directly correlated to strength.
Toughness is the ability to resist damage like cracking and or chipping when impacted.
Wear resistance is the steel’s ability to withstand damage from grinding, rubbing and debris adhesion.
Corrosion resistance is the ability to resist corrosion such as rust caused by exposure to elements like moisture and salt.
Edge Retention equates to how long a given knife blade will hold its edge when in use.
We have focused on the three major steels and of course i hear you asking what about titanium, Damascus, san mai even ceramic, which while deserving a full post in their own right, for instance you can read all about Damascus steel here, these blades fall under the category of exotic material blades, titanium ( not to be confused with titanium steel which is basically just another flavor of stainless steel) and ceramic being non steel and Damascus and san mai being folded / laminated steel.
So you’ve read this far i am sure the burning question on your mind is which steel knife blade is best?, that basically comes down to usage, just what are you going to use the knife for?, yes i answered a question with a question, but this is the key element in your decision, its worth noting here that most modern steel knife blades perform well no matter what the task at hand, so pay attention to how the knife handles and its envisaged use. The shape of the knife blade and its handle are also key elements in a knife’s performance, remember that there was a time when your knifes intended job was done by chipping and flaking off bits of rock to make an edge.
Do not let yourself get bogged down in the endless variety’s of steels and exotic materials, the same type of steel can differ widely from one manufacturer to another, think of what you want the knife to do, is it a display / collectors piece?, then by all means treat yourself to some Damascus or san mai, going diving?, then corrosion resistance is key.
I do a lot of hunting and camping and while i have tried many many different hunting knives over the years i always come back to my trusty Bowie knife, the number one all rounder, maybe a little heavy duty if your out to fillet a sardine but i have yet to meet the job it cannot handle, mines a stainless steel bladed Bowie if your wondering. With some general knowledge and a little trail and error you will find the right knife for you.
Of course this article would not be complete without touching on blade coating.
When it comes to your new knife, one would be forgiven for thinking that the various blade coatings are purely aesthetic and in fairness sometimes this is the case, however properly coated knives offer many advantages, certain coatings will add strength, some durability others help prevent corrosion.
Speaking in strictly general terms, the finishes and coatings will enhance your blade and help extend the lifespan of your new knife. You can shop Knives Ireland here.