"Stainless" vs "Carbon" steel

I really liked 40CP as well. 440C was good steel, and applying powder metallurgy manufacturing to it really did make it shine even more. You're definitely right though, virtually all steels are tradeoffs.

 

I've been seriously into knives as a hobby for 14 years, and I can't answer your question. If you're interested in the toughness question mostly, there is an interesting Bladeforums experiment going on right now. People are sending heat-treated Charpy testing samples of different cutlery steels in to a member who has access to a testing unit. We're hoping to collate toughness data against steel type, hardness, and heat treat protocols.

 

Nope. No stainless I've seen comes close to the beauty that is possible with a carbon steel blade. For example -



This is a "plain" example.

 

I think Damasteel's DS93X powder metallurgy stainless damascus is the best-looking production damascus short of Bernie Rietveld. Very bright contrast. That's some high-performance stuff made from RWL34 and PMC27, roughly equivalent to CPM154.

 

Word... Im following this one myself. I have experienced various knife steels over the years of my life. while I generally prefer high carbon steels, some of the modern stainless blades seem to have good reputations- including a not-cheap Chinese knife I own- one of my few stainless blades. Blade metallurgy has come a long way since my youth and Buck knives.

 

That a Reate? Several of the new Chinese brands are really knocking it out of the park. Some small businesses with owners who are really passionate about knives. Glad to see that emerging there. I won a Reate K-1 in a post-pass around giveaway on Bladeforums, and it's really a fantastic knife.

 

The brand name of the knife in question is a Hanwei "Rock Creek" with a HWS-1K forged blade, with a hardness of 58 HRc – 60 HRc and has a sambar stag grip. It takes a very nice edge and seems to hold up well. I paid something close to $100 for it as I recall.

 

Hanwei makes good entry-level swords. They're among the most function of the factory swords. I don't know too much about their knives, though, I would assume they are of equivalent quality. Glad you enjoy your knife!

 

No. "High carbon" is not a great name. In hindsight, we could maybe have called it "chromium-free" steel, but we started calling it "high carbon" in comparison to milder steels with say 0.3-0.6% carbon content, before chromium steel was common in industry.

Trivia: The chromium in the steel doesn't form large carbides until the carbon content exceeds 0.8%. So stainless steels like 8CR13 (which has 0.8% carbon) and other stainless steels with low carbon content, like AEB-L, do not have big chunks in the peanut butter, so to speak. It's where the carbon content gets higher that this becomes an issue. And this is where sintered steels come into play. The powder sintering process is one way to reduce the size of the carbides. And now we have stainless steels with carbon up in 2% range which can take a razor edge. So even in stainless steels, there is an important distinction between high carbon and low carbon, but that name is already taken over by chromium-free steel, in general.

This is all the result of chromium steel being named with a modify "-less." Now that we have stainless steel, the other flavor would be "non stainless" which is a double negative and sounds bad. OTOH, calling it "stain steel" is maybe even dumber. So we call it what we always called it, even though high or low carbon also technically describe stainless steels.

 

Well, you seem more versed in the various stainless steels than I. I'm still gonna add my two cents

The main reason I have seen for the high-carbon steels is toughness and the ability to strike sparks on flint (e.g. Dave Canterbury). Personally I generally favor stainless for EDC and 'wet' activities like fishing, kayaking, etc. For everything else I'm partial to S30V and S35V but I have many knives in other steels (D2, 5160, 1095, etc). My main EDC is a Grohmann's D.H. Russell Canadian profile in their 4110 'high-carbon' stainless. My main everything knife is a custom S35V and my goto hunting / survival knives are S30V, 5160 or D2.

 

I'm going to kick in some data from Bladeforums. This is a project that's been sort of crowdsourced and funded at Bladeforums to provide objective, comparable data. It's a work in progress, and the hope is to have lots and lots of different steel samples.

 

Look for heat treat certifications. You may not find them under brand specific names.

 

I read OP's question as relating to semantics to a great extent, i.e. why call carbon steel by that name when many modern stainless steels contain just as much if not more carbon. Not so much a request for understanding how to pick the best steel for a job as just wondering about the nomenclature. Sorry if I am mistaken.

In any case one can think of carbon steel as ONLY CARBON or carbon but not stainless. Stainless steels with relatively high carbon contents are still dominated by the characteristics imparted by the chromium and or nickel. So we could say "just carbon steel" for the non-stainless variety and "carbon plus nickel/chromium" for the stainless variety, but why bother? We just use the shortcut names, carbon and stainless.

In the above do not presume I mean that there are not trace or minor amounts of various elements in all steels. In this discussion I am simply focused on the ingredients that most significantly relate to the common names of the alloys.

 

What you are looking for is an MTR or MTC. A materials test Report or Materials test certification. It’s a type of destructive analysis that provides a breakdown of a materials contents. An internationally accepted method was developed to certify an alloy based on its contents. For every single bar or plate out of a material a cert is made for traceability a batch number is provided. In the event of catastrophic failure all of a heat# may be pulled. Industries such as petroleum aviation and structure require accountability of certification. Some times on specific jobs a customer will require not only mtr/c documentation but also procedural reports for established condition. Such as level of heat treat and certified process control. Any steel will go through a properties change when enough heat or other material is exposed or applied.

I have been a machinist for twenty years, I have a drafting degree and am also a fitter welder. I have done work under a lot of conditions and certifications in multiple industries. API 6a in the oilfield. AISC in construction and several ISO certified shops. I have also done materials and data selection for purchasing.

I can write up a better explaination for the comparison of properties and try to solve this age old debate more technically but I need to sit down and work it over after I get to the shop. I shouldn’t be typing all this with one hand doing 70 on the hwy.

As well as being passionate about metal working I’m a bit of a nerd about history and theology. So pardon me if I wax a bit poetic in my explainations today. Here goes nothing. Ever since the dawn of time man has been on a quest to find the most useful tools possible. At some point he slipped the bonds of earth and learned to pass into her belly and extract her scattered and elusive contents. At first he discovered copper and then discovered the ability to make alloys and bronze was made. He saw that it was good when sharpened. Knives swords and tools were constructed. Some where farther away iron was discovered. And so the first battle over superiority was not Ak Vs AR or 9 vs 45 or 1911 vs Glock but Iron Vs Bronze.

Also this particular war included the concept of softness vs hardness wear resistance vs sharpness. You have to have a balance between the two. The first discovery of pattern welding steels helped to increase the usefulness of these iron tools because they would hold an edge better yet not be as brittle when banged against other swords and blades.

Back on subject sort of, so we spanned the gap between 3k before our Lord to about 800 after. Now I’m ganna skip a bit and try to get more to the point. We learned to alloy materials. I realized many of you may not want to know that much of the story.

All metals as we know them now unless specifically made for it are alloys. Part of what we need to understand is the hardening process as is applied heat and quenching either with air exposure, oil or water. Sometimes in carbon steels more carbon is introduced via the hardening in oil. A good bit is introduced via the smelting process. The key is temperature control and timing. Part of the process is the realigning of the molecular structure. Some of that occurs ins hammer forging. But the heat treat us everything in the higher content hard to hammer materials. The other thing you can do is add other metals like chromium, cobalt and nickel. Those are also some of the things that they add to certain blends of stainless.

You have austenitic, martinsitic and ferritic stainless alloys. They each have different properties that have benefits. Wear resitistance, heat control and ductility. Some stainless is much cheaper to produce than others. This is where we get into the thick. To produce a better quality carbon steel blade is a little cheaper and easier than to produce a cheaper but quality stainless. I believe this is the root of the issue. Comparing an American budget carbon ( Schrade USA, back then) vs a Chinese or Afghanistan made cheap stainless is a no brained decision. But compare all to a Japanese or German stainless? No contest.

 

Different steels perform different jobs better.

Stainless steels (broad generalization coming) tend to be harder and as such have better edge retention and are more prone to the edge chipping rather than rolling. Typically stainless steels excel in smaller knives/pocket knives etc.

Carbon steels (another broad generalization) tend to be softer. The edge is prone to rolling and is actually pretty difficult to chip. Typically carbon steels are better used in larger blades (softer steel the larger the blade).

Tool steels are all over the place and behave more or less like either carbon or stainless depending on the alloy of the steel.

Can you make a softer stainless steel and use it in a large fixed blade knife? Of course, but it's not going to be for the same price point as carbon steel and the only real gain is a bit of rust resistance.

Can you make carbon steel as hard as stainless? Not that I'm aware, and honestly I wouldn't see the point.

Also as a side note I'm not a big fan of the super steels. Even with a diamond sharpener it takes me the better part of an hour to get some M390 to popping hairs.

And anyone thinks any given steel is superior for all tasks, use a knife made out of a hard stainless steel as a crowbar some time. Or for that matter see how long you can keep an edge on 1095 (or another carbon steel) while cutting card board.

 

I don't know about considering tool steels carbon steels. Their chemical makeup is closer to stainless than to the typical carbon steels. But I do appreciate the insight on tool steels, I hadn't heard about the deceased chipping in high end tool steel vs high end stainless.

Including chemical makeup examples

CPM M4 Tool Steel:
1.42% Carbon
4% Chromium
5.25% Molybdenum
4% Vanadium
5.5% Tungsten
.3-.7% Manganese
.06-.22% Sulfur

1095 High Carbon Steel:
.9-1.03% Carbon
Less than .05% Sulphur
Less than .04% Phosphorous
.3-.5% Manganese

M390 Stainless Steel:
1.9% Carbon
20% Chromium
.3% Manganese
1% Molybdenum
.7% Silicon
.6% Tungsten
4% Vanadium

 

Personally, I'm a fan of CPM 3V (Bark River - small knives) and I want to try a 4V but have not (yet). Most of my small EDC knives are a variety of stainless (D.H. Russell) because of the moisture exposure. While looking into this post I found these two links very interesting.:

https://www.bladeforums.com/threads/cpm3v-vs-cpm4v.1225549/

In this post, they are equating 5160 with 1060 which surprised me but it seems logical in retrospect.

https://www.bladeforums.com/threads/carbon-steel-question-5160-vs-1060.529179/

My large knives are mostly 1095 or 5160. My 5160 knives are Buck Hoodlums designed by the late Ron Hood. In this case, the design of the knife was the important factor (great light camp/survival knife with fighting potential). My other large knives are in 1095 (ESEE - heavy choppers). My medium knives run mostly D2 (Knives of Alaska - small to medium skinning/fillet/game processing). I also have a modified A1/A2 Bowie that runs well.

 

I need to branch out into some tool steels. Right now I have 2, an Esee 6 and Izula, in 1095. A Benchmade in 154 CM and another in M390 and a Himalayan Imports Khukuri in (probably) 5160. Not a very diverse mix.

 

Well, for EDC I need a stainless, there's not really a choice. For a general-purpose knife, I want the CPM3V and usually go Bark River and I find the best deals at DLT Trading:

https://www.dlttrading.com/searchresults.html?Search=&search_query=cpm+3v

https://www.dlttrading.com/bark-river-overstocks-discounted-knives

But I find the design of Knives of Alaska better and also they are generally 1/2 the price. However, they're mostly available in D2 (and this is fine, a balance between ease-of-sharpening and hardness).

I do have this set on backorder though (should be in stock very soon):

https://www.knivesofalaska.com/item.asp?id=12

You can also get the Alpha Wolf separately.

For large knives, I think a tougher steel is in order so I generally go high carbon.