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Sasquatch Valley Knife Materials FAQ
What is the best steel used in a knife?
You will hear many knife sellers or magazines raving about some new steel that is superior to all others but the fact is that there is no one magic steel for a knife. Each different mixture has different properties such as hardness, corrosion resistance, machinability, and brittleness. What is the best steel for opening boxes may not be the best steel for field dressing an elk. What is the best steel for a tactical knife isn't always the best steel for ocean fishing.
Is a harder steel always a better knife?
A harder steel will retain its edge longer but is more difficult to sharpen and may even require a diamond sharpener to file. Softer steels may dull more frequently but are easier to sharpen with even common hand sharpeners. Harder steels also cost more to cut knifes out of so often they are either more expensive, imported or both. Also consider that the military doesn't exceed 440 stainless in any their knives commonly issued. It often amuses me that people will talk down 440 stainless in favor of a more hi tech steel like ATS 34 and in the next breath rave over a Marine KA BAR that uses high carbon or a Seal SOG that use 440.
For me personally, 440 is the minimum steel I'll use myself. I will also use the AUS equivalent. I don't ever use a steel harder than ATS-34 (like ATS-55 or BG-42) because these are even difficult to sharpen with a diamond file. But this is just my personal taste. This guy just was telling me that a SOG Recondo (with BG-42 not even the titanium nitride version) that he bought went through all kinds of hell, like digging, chopping branches, stripping branches, hammering tent stakes and carving wood, and still was sharp. However, a hard steel may be more sturdy it also tends to be more brittle (likely to shatter).
A Rockwell is a measure of hardness. This is number is determined by a diamond being drilled into the steel under a constant pressure. The higher the Rockwell Number, the more resistant the material.
Knifes that have been Rockwelled will have a small dent drilled into them to conduct the test. If the Rockwell test was actually done on the specific knife I'm selling the Rockwell will be a specific number (eg. 57), if the number is a range (eg. 56-58), this is the average Rockwell of these types of knives plus a standard devation. Most companies do not Rockwell test each specific knife but some brands do, like Puma.
The Rockwell range that I personally prefer is 56-60, as anything lower is too soft and has poor edge rentention and anything harder has the flaws mentioned in the above question. Many people swear by 420 which Rockwells below 56 but these are people (like chefs & hunters) who sharpen their knives all the time. If you don't have a sharpener, stay with 56+. If you don't have a diamond sharpener, stay below 60.
420 stainless steel is extremely stain resistant due to a low content of carbon but it is fairly soft so it doesn't hold an edge as well as harder knives. Because they are made from a softer steel, they are easier to manufacturer and thus cost less than a harder steel. 420 is used most often in diving knives and in some survival and fishing knives--anywhere that the knife can be exposed to salt water. You will also see 420 in old traditional style pocketknives and kitchen knives. 420 is also easy to sharpen which may be why it is popular with chefs & hunters.
440 stainless steel also resists rust but not quite as well as 420. It is harder and holds an edge longer. It is more expensive to manufacture than softer steels. 440 stainless comes is three strains: A, B and C, each sucessive strain has a bit more carbon and thus is slightly harder and slightly less rust resistant. 440 stainless used to be the industry standard for high quality knives but now some of the more high tech steels have taken it over in popularity. 440 is in my opinion one of the best steels to get and the differences between the strains are of little noticeble difference for the average user. The name 440 originally refered to only US made steel but close match steels are often sold under the name 440 such as the AUS series. 440A Rockwells around 55-77 where 440C Rockwells around 58-60.
Japanese stainless steels which are very close to the 440 series there is a numbered series that roughly corresponds to the 440 series in the AUS; AUS-6 is like 440A, AUS-8 is like 440B and AUS-10 is like 440C. The AUS steels differ from 440 mostly in that there is vanadium added, which should improve edge retention and wear resistance.
GIN-1 is very similar to ATS-34 but with slightly less carbon and much less molybendum than ATS-34. GIN-1 is slightly more corrosion resistant than ATS-34. Used occasionally by Benchmade & Spyderco.
Similar to ATS-34 but without hardly any Molybendum, which is mainly used in high speed steels and is expensive. Since knives do not need to be at high speed the Molybendum was taken out and replaced with cobalt and copper to increase edge rentention. ATS-55 rockwells around 60-62. Mainly used by Spyderco.
ATS-34 is the most popular stainless steel now. It has a high hardness but is less resistant to rust than the 400 steels. It is very good for wear resistance but is difficult to sharpen. It holds an edge well and Rockwells around 59-61. It is made in Japan by the Hitachi company. 154-CM is the American version manufactured by the Crucible company. ATS-34 has quite a bit Molybendum in it, Molybendum is typically used in high speed steels and it imparts abrasive resistance to the steel. Spyderco uses ATS-34 frequently. Benchmade uses 154-CM.
BG-42 is similar to ATS-34 except with the addition of vanadium for more edge holding ability. You can find BG-42 in custom knives and some SOG knives. BG-42 is manufactuered by the Latrobe company and was originally used as a high performance ball bearing steel. Custom knifemakers have been raving about BG-42 lately because it has all the features of ATS-34 but with a smaller grain which polishes better. BG-42 rockwells at 61-63.
High Carbon / Non Stainless Steels
1095 An alloy of iron, carbon and manganese. It is a fairly tough steel that is excellent at holding an edge. Used in the KA-BAR. It rusts easily, which is why it is often coated.
M2 is a tool grade steel used for high speed cutting of steel. It has very high wear and abrasion resistance so it holds an edge well. It rockwells around 60-65.
D2 has a very high carbon content but is more resistant to rust than the other high carbon steels because of a high cromium content, but it is not stainless. It has a good edge holding but is not as hard as some of the other high carbon steels. It rockwells around 57-61. Ka-Bar makes some fighting knives out of D-2.
Non Steel Blade Materials
Some knives are made out of clays, some similar to the materials sharpening stones are made out of. There are a few makers of this for kitchen knives, that are supposed to never dull. However if they do dull, there is no way for you to resharpen them.
Obsidian is a volcanic glass traditonally used in "stone age" cultures. Obsidian knives are flaked to have a serrrated like edge which when chipped keep sharp. These are like having a piece of broken glass to cut with. Outside traditional prehistoric knives obsidian is sometimes used in Surgical Scapals.
Titanium alloys can Rockwell at almost 50 but this much lower than even the softest stainless steel. Titanium is very rust resistant and also non magnetic--this is why it is used by Underwater Demolition military forces because mines that they deactivate will explode if they sense metal. While some people who watch a lot of movies rave over Titanium, you wouldn't really want a knife (much less a sword) made out of titanium because they can't keep an edge. Unless you're disarming magnetic mines stay away from this expensive metal.