Is there a reason there are no carbon steel folding knives?

knarfeng said:
Aogami Super Blue would fall into the "Low Alloy steel" category.

It has less than 10% alloying elements.
Click to expand...

It might not "technically" be carbon steel, but it seems to be able to take a patina easily and have the properties I like, so I'd still be quite happy enough with a folder in it. :thumbup:
 
I guess most companies that make modern style one hand opening folders use stainless steels because that's what their customers prefer and high quality stainless steels perform really well in pocket knives. Some carbon steels or other non-stainless alloy steels shine in hard use fixed blade knives since they are quite tough, but that advantage is lost in folding knives which aren't subjected to that kind of stress.

For some reason, I prefer stainless steels like S30V in my "modern" folders and non-stainless steels like 1095, 52100, etc. in my traditional folders (slipjoints, friction folders and such). It just feels right. However, I do wish somebody made more traditional style slipjoints with high quality stainless blades (I know, the opposite to what the OP was asking for), I live in a horribly hot and humid city.

Anyway, besides the Spyderco Gayle Bradley and some Benchmades in M4, Case makes a couple of their one hand opening designs in CV (Russlock and Trapperlock, kinda hybrids between traditional and modern).
 
knarfeng said:
The question gets confusing when folks use the wrong terms.

There is stainless
There is low alloy steel.
There is non-stainless High alloy steel.
There is Carbon steel.

None of these terms is actually interchangeable.

D2 actually qualifies as "Stainless"

Case CV and KaBar 1095 Cro-Van alloys are "low alloy steel".

CPM M4 is "high alloy non-stainless".

1095 is "carbon steel".
Click to expand...

D2 is 12% chromium if I'm not mistaken. I've read that for a steel to qualify as stainless it must have minimum 12% chromium, I've also read it must be 13%. I don't know which one of these is true. I have very limited experience with D2, but have read that it will rust?

So is D2 stainless? Or is it tool steel? I've been confused on this point for a while.

Also, I believe that the Benchmade Adamas is D2. But if D2 is stainless then I guess it doesn't count.
 
The minimum chromium content required for a steel to be classified as stainless tends to vary a bit depending on who you ask. This is reasonable considering that the property of resisting corrosion is a sliding scale. It is not of case of either it is or it isn't. Stain resistant properties begin showing at about 10% chromium content. If all other element concentrations are held constant, then the higher the chromium content, the more corrosion resistant the alloy is.

I use Key to metals as a reference for such matters. They are a database for metallurgists. They also have reasonably definitive articles that you can access and read without being a member.

Low-alloy steels constitute a category of ferrous materials that exhibit mechanical properties superior to plain carbon steels as the result of additions of alloying elements such as nickel, chromium, and molybdenum. Total alloy content can range from 2.07% up to levels just below that of stainless steels, which contain a minimum of 10% Cr.
Click to expand...
http://www.keytometals.com/Articles/Art62.htm

Per the AISI specification for D2, the alloy must contain between 11 and 13% Chromium.
http://www.efunda.com/materials/all...ol.cfm?ID=AISI_D2&prop=all&Page_Title=AISI+D2

That makes D2 "stainless steel", even if it is at the low end of the chromium content range, making it not as corrosion resistant as other "stainless alloys".
 
I have this knife in 1095..... One of my favorites! Its a great knife and I have not had any problems keeping the blade rust-free


image.jpg
 
Last edited:
knarfeng said:
The minimum chromium content required for a steel to be classified as stainless tends to vary a bit depending on who you ask. This is reasonable considering that the property of resisting corrosion is a sliding scale. It is not of case of either it is or it isn't. Stain resistant properties begin showing at about 10% chromium content. If all other element concentrations are held constant, then the higher the chromium content, the more corrosion resistant the alloy is.

I use Key to metals as a reference for such matters. They are a database for metallurgists. They also have reasonably definitive articles that you can access and read without being a member.


http://www.keytometals.com/Articles/Art62.htm

Per the AISI specification for D2, the alloy must contain between 11 and 13% Chromium.
http://www.efunda.com/materials/all...ol.cfm?ID=AISI_D2&prop=all&Page_Title=AISI+D2

That makes D2 "stainless steel", even if it is at the low end of the chromium content range, making it not as corrosion resistant as other "stainless alloys".
Click to expand...

Ok, thanks for the info. Do you have much experience with D2 in every day use? I know that it is supposed to have great edge retention, but how does the corrosion resistance compare to some other steels. Specific steels that I am familiar with would be AUS 8, 1095, Sanvik 14c28n, CPM S30V, and VG 10.

I know it will rate higher than 1095, that being a carbon steel, but how is it compared to the other stainless alloys?
 
D2 isn't as stainless since it has ~1.5% carbon, so there isn't as much free chromium in the austenite for passivation. Most knife steels need around 13% chromium because of the carbon content leading to more chromium carbide.
 
how does the corrosion resistance compare to some other steels. Specific steels that I am familiar with would be AUS 8, 1095, Sanvik 14c28n, CPM S30V, and VG 10.
Click to expand...

D2 is less corrosion resistant than any of the steels you mention. I've read the fellas say that D2 will form a patina if you work real hard at it. I have a number of D2 blades. (I'm partial to Queen knives.) One has single a black spot on the blade, which I have not bothered to polish away. None of the others have any spots. I do not oil the blades, though I do oil the joints.
 
goodeyesniper said:
there are custom makers who work in carbon steels who won't exactly break the bank. They are usually more traditional, but these michael morris friction folders can be operated with one hand and are sexy to boot. (made from old files, so they might be considered tool steel, not simple carbon?)
Click to expand...

do want.
 
Spyderco are doing a run of HAP40 knives, a tool steel that is a higher alloy relative of M4. It's not 'carbon steel' but it'll probably rust up easier than a stainless.
 
There are a lot of companies that use carbon steel in their knives; knives that are not slipjoints. Knives of Alaska uses D2, which is semi-stainless. Also, a lot of the Swedish and other Scandinavian knife companies use carbon steel in their folding knives and fixed blade knives.
 
In my opinion you don't see much carbon steel folders, because they are supposed to be easy to maintain.
I would not have a knife that I carry regularly and have to clean every night I store it.
I have a Mtech folder that I carry on hunts with me and I have to clean it thoroughly else it catches rust.
 
EDC5-30-12-1.jpg
 
knarfeng said:
D2 is less corrosion resistant than any of the steels you mention. I've read the fellas say that D2 will form a patina if you work real hard at it. I have a number of D2 blades. (I'm partial to Queen knives.) One has single a black spot on the blade, which I have not bothered to polish away. None of the others have any spots. I do not oil the blades, though I do oil the joints.
Click to expand...

D2 can rust under minimally humid conditions, New England winters have been rough on my D2 pocketknives. It's also possible to force a very nice even patina via a 2-3 hour bath in cheap vinegar. It's definitely not comparable to a carbon steel, but it's not exactly stainless either.
 
Last edited:
There is (sorta)

D2
3V
PD1
M4

But I would love to see more folders in 1095 and 52100.

John Mcnees and Sniper Blade Works make a lot of their folders in 1095, but they come with a big price tag.

It would be really nice to see anything from a Spyderco to RHK's or SKI's in a true high carbon steel.

They would sell like crazy......
 
I always figured it's because folding knives have more moving parts and can develop rust in the pivot area which could cause a bit of grit.

Fixed blades are much more simple, so carbon steel is more viable.
 
You must log in or register to reply here.
Back
Top