"Stainless" vs "Carbon" steel

I'm gonna follow this thread as during the course of my research (as an old guy who only in the past couple years starting getting into knives) I came up with the same question, but felt a bit timid about bringing it up ...

Ease of sharpening is definitely not a small benefit by any means, especially on the field. To stretch it further - in general, carbon steels give you the benefit of successfully using much wider range of sharpening materials, while most of the high-end stainless blades are pretty much limited to diamond stones. And the cost IS a limiting factor - the premium that is payed for a high-end steel sometimes gets double, or even triple the price, compared to a knife with a blade of more "peasant" steel from the same manufacturer. Those steels are still expensive and they require extensive & complicated heat treating, that reflects to the cost. Not to mention, that I'm not sooo much impressed with the performance of the super-steels - yea, sure, they can hold an edge better, cut numerous pieces of manila rope (like I need that for some bizarre reason...) and blah, blah, blah, but the "every day" performance is really not that much better compared to a good carbon blade. I mean, they are definitely better, but it's nothing so exiting to write home about. It's just steel - it gets dull with use.

There are more variables than just metallurgic content but yes I agree its not as simple as Carbon vs Stainless.
The first knife with SV30 I ever had was a Phil Boguzewski custom (Tim Wegner design). And with all the glowing adoration of the new steel by the knife community I hated it. Great geometry overall but would not take a good edge. It even went back to Phil and he couldn't make it work either. It was like it could shave but not cut in a draw stroke. Heat treat and edge geometry and sign of the moon, whatever. There is a lot that has to come together to make a great knife. I think its not hard to make a really good knife, but a great knife is tougher to do. I do think more and more people are getting better at it.
I haven't stayed current. I see more steel formulas that I know nothing about. But put it my hand and let me use and use it some more and I can tell you if I like it.

It's a function of diminishing returns- price vs. performance. Add in the aforementioned difficulty to sharpen, and you can see why the 10xx series of carbon steel are preferred for most work. They do the job, and are easy to sharpen.

Kingcreek said:

Great geometry overall but would not take a good edge.

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Sv30 is the hardest to sharpen that I own, or would put up with.

I like trying out the newer fancy steels. Stainless ones like XHP, zdp189, and s110v. Even ones that are not stain resistant such as m4. Sure, they are tougher to maintain and probably way beyond what I need in performance level, but I like nice things.

Why do some of use spend over 1000 bucks on a 1911? A HiPoint will do most jobs just fine and you dont have to worry about keeping it pretty.

Bill Bagwell's book on Bowie knives discusses carbon steel vs. stainless steel, and concludes that 154CM is a poor choice for a knife blade. He wrote that the "super steel" claims were mostly marketing.

For me, if it's just an edc folder that is not subject to hard use, then 154CM or VG10 is good enough. Also, I hate taking apart folders so the easy maintenance of stainless is nice.

But all of my large (bigger than 9" blade) knives and my hard use knives are all high carbon steel. Strength is more important than cosmetics for these knives.

The big advantage would be strength. Plain carbon steels will bend before they break, but stainless steels will fracture. That being said, I still come down on the side of stainless steels for all but the biggest applications because I find the decreased maintenance to be worth the decreased toughness. Good stainless steels are plenty tough enough for any reasonable use of a cutting implement.

Of course, you don't really have to sacrifice there. Nitro-V is stainless and as tough as 5160. Is it as tough as 3V? I don't believe so, but nobody ever said 5160 was a slouch for large blades, and it's still a sword maker's go-to steel, so if Nitro-V is that tough and stainless, I think that's a winner.

My “good knives” are high carbon steel and are treated very well washed dried sharpened and oiled then put away until I need a “good knife”.For every other day of the year I carry a Buck or similar still a good knife but not so picky about care as long as its sharp.I own a lot of knives as many as 40 but less than 6 that I use.Sv30 is the hardest I care to own too and it doesn’t hold an edge any longer than my best high carbon blades but it is warranted for life and thats not a bad thing.

Would that site be of any help to you? http://www.zknives.com/knives/steels/steelchart.php

JohnKSa said:

the carbon content of stainless steel was limited due to issues related to the high chromium content that defines stainless steel. If someone has a good explanation of that limitation, I would really like to hear it.

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Here's page I referenced to find more about carbon steel vs stainless steel which states carbon steels contain less carbon than stainless steels yet stronger to hold sharper and more defined edge (read comments for 1095 carbon steel) - http://tomahawkdb.com/types-of-steel.asp

I like to cook (often daily) and can only comment on cooking knives I use which are Wusthof, Victorinox, Kuma, Cuisinart and Kitchenaid. I use poly cutting boards which are hard on knife edges and my batches of chili con carne, chili verde, beef stew will often use 8-16 lbs of meat for potlucks at work.

I use 600/1000 whetstone to sharpen my knives and with heavy use, I found I need to resharpen Cuisinart/Kitchenaid knives more often (several times a year) which are advertised simply as "german" stainless steel. With Wusthof/Victorinox/Kuma knives, I usually only need to hone the knife edges and require resharpening perhaps 1-2 times a year. Wusthof uses X50CrMoV15 while Kuma uses 3Cr13 stainless steel - https://www.wuesthof.com/internatio...eving-the-perfect-hardness-and-sharpness!.jsp

Surprisingly, my current favorite knife is Kuma which holds an excellent edge even under heavy use and feels most balanced in my hand. I like it so much that I bought two more knives to use in both indoor and outdoor kitchens.

JohnKSa said:

I don't know when his book was published or what steels he was talking about, but there does seem to be a consensus that the super steels offer performance benefits over more conventional alloys, even from the consumer side vs. exclusively from the marketing side.This hits on two points I'm interested in. First of all, virtually all of the "super steels" are high carbon--they have carbon content that equals or exceeds that of the "non-stainless carbon steels" out there. Second, I'm very interested in the relative strengths of the various knife steels, but so far I can't find conclusive evidence that the current crop of premium stainless steel alloys give up anything to conventional carbon steels in terms of strength.I would really like to see some relative strength information for the various steel alloys out there. I hear people making comments about conventional carbon steel being stronger and I would like to both confirm this fact and also to understand why it is true.This seems very odd since Nitro-V does not have particularly high carbon content nor is it a particularly exotic alloy composition. This is the kind of thing I'm talking about. Why would Nitro-V (0.68% Carbon, 12.98% Chrome, 0.079% Vanadium, 0.1% Nitrogen, ...) be tougher than say, 154CM (1.05% Carbon, 13.5-14.0% Chrome, 4% Molybdenum, 0.4% Vanadium, ...) or ATS-34 which is very similar in composition to 154CM? One would think that the higher carbon, higher Vanadium and the addition of Molybdenum would make those steels tougher. Is the nitrogen addition to Nitro-V really enough to more than make up for the lower carbon, vanadium and the lack of moly?

I'm really hoping that I will get some explanations, or maybe some tips on where to learn more about the topic.

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I'm just an amateur, not a metallurgist. I can't point you to any sort of testing, although there's all kinds out there. I can really only testify to what I observe as trends with knife makers, buyers, and users.

There are a couple confounding issues here:

1. There are a lot of factors that are balancing acts in what makes a steel "good" for cutlery, and even in what makes a steel "strong." Alloy composition is only one of them, and even that is super complicated because the relationship between the amount of an alloy ingredient and the general effect of that element's inclusion in steel is not linear and also is dependent on the steel manufacturing method.

For example, everyone knows chromium is the element that makes stainless steel (when included at more than 13%). But, if the steel is manufactured such that the chromium mostly ends up in carbide form instead free, it will have very little stain resistance.

Likewise, carbon increases hardenability and of course is what makes an iron alloy 'steel.' But hardness and toughness are inversely related, so increasing carbon content and thus the maximum hardness attainable by the steel alloy produces a reduction in toughness as well. But... steel alloy ingredients don't act in a vacuum. So more exotic elements can increase toughness or decrease it as well.

2. Direct comparisons are difficult because you would need to test the exact same knives in the exact same method, just with varying steels, because edge geometry and blade shape affect efficient performance at any given task even more than material does.

3. There's no central clearinghouse for this kind of information, just a lot of common wisdom based on collective experience (and collective mythology, admittedly). All I can really tell you here is that while there are tough stainless steels, non-stainless tool steel alloys and simple carbon steel alloys are almost universally regarded as tougher. There are very few positive qualities in a cutlery steel that can be had without a decrease in some other desired quality. Because stainless is corrosion-resistant, it gives up ground on tougness.

Personally, I don't think it matters too much on most reasonably sized knives. I would not like stainless on swords or axes or large knives intended for chopping high-hardness objects, but even on a 7" camp knife, I think a modestly tough stainless is sufficient for virtually any use.

I thought I saw an interview in which Ethan Becker commenting that ka-bar added chrome, vanadium, etc. to their 1095 carbon to improve the grain quality of the steel (IIRC?). I don’t know if this affects steel density or something else, but I’d guess that it’s part of their claim of good quality carbon knife steel that sets their 1095 cro-van steel apart from other regular 1095 carbon knife steel. Interesting thread.

Way to go, Ka-Bar - after another several decades they might discover BS-1407, or Aogami Super... You know, just maybe...

Mizar said:

Way to go, Ka-Bar - after another several decades they might discover BS-1407, or Aogami Super... You know, just maybe...

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Yup, and maybe they’ll discover how to apply a proper bevel, too.

Madcap_Magician said:

2. Direct comparisons are difficult because you would need to test the exact same knives in the exact same method, just with varying steels, because edge geometry and blade shape affect efficient performance at any given task even more than material does.

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I agree.

This comparison video is what got me introduced to Kuma knife with 3Cr13 stainless steel (Carbon .3% and Chromium 13%). I have used the Kuma knife for over 9 months under hard use on poly cutting boards, and so far, I am more than satisfied how it has performed. I sharpened the Kuma knife out of the box with 600/1000 whetstone and it has not needed resharpening other than occasional honing.

Mercer Renaissance knife with supposed X50CrMoV15 stainless steel (Carbon .5% and Chromium 15%) the same as Wusthof with hardness of 58 Rockwell - https://www.amazon.com/Mercer-Culinary-Renaissance-8-Inch-Forged/dp/B002R1CGV6

Mercer knife with X30Cr13 stainless steel (Carbon .3% and Chromium 13%) with hardness of 56 Rockwell - https://www.amazon.com/Mercer-Culin...rd_wg=cRmBd&psc=1&refRID=EBWCCZED6V4FE7P4HAS2



And comprehensive "Top Picks For Best Kitchen Knives Of 2017" video

Mizar said:

Ease of sharpening is definitely not a small benefit by any means, especially on the field.

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My favorite field knives are by choice, carbon steel. They sharpen easily in the field. For me, stainless is better for the kitchen.

You can’t find it possibly because that’s a trade secret of knife steel manufacturers. Just a guess.

JohnKSa said:

Ok, let me start by saying I'm not a metallurgist--this is just the result of some research (poking around on the web, if you prefer) and my thoughts.

In my other thread about stainless steel knives, the discussion prompted me to start thinking about the topic and I've spent some time looking at various charts that show the composition of common knife steels. Naturally, some of that time was spent comparing the carbon content of "carbon" steels, "tool" steels and "stainless" steels.

I don't understand the details, but I believe that at one time, the carbon content of stainless steel was limited due to issues related to the high chromium content that defines stainless steel. If someone has a good explanation of that limitation, I would really like to hear it.

At any rate, I believe that some of the new techniques for making stainless steel alloys have bypassed this limitation resulting in stainless steels that have very high carbon content.

For example, CTS-XHP has a carbon content that exceeds that of 1095 carbon steel, and that actually matches the carbon content of D2 tool steel. Some stainless alloys, like ZDP-189 actually have carbon content that far exceeds the common "carbon steels" and is only matched by a few tool steels.

Looking at hardness numbers, it appears that a lot of the premium stainless steels actually outperform all the conventional carbon steels and even many tool steels.

So...

Does it really make sense to keep talking about carbon steel vs stainless steel like there's a practical difference between the carbon content that gives the carbon steels hardness advantage? Because it appears that both in terms of carbon content and hardness, there are many premium stainless steels that directly contradict that pretense.

It appears (to my admittedly amateur eye) that when the real differences between carbon steel and stainless steel are evaluated, the only real benefits of common carbon/tool steels, are ease of sharpening, cost, and perhaps ease of forging. In all of the other performance areas, as far as I can tell, the premium stainless steels have a decided advantage.

Thoughts?

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I was one of the knifemakers that was involved in testing XHP before it was even available for sale. It was explained at the time by Carpenter metallurgist as a true stainless D2 or a high carbon 440C. It's sort of cross between the three made via powder metallurgy. It has taken the knife world by storm since then and IMO is the best performing stainless steel for a high end user knife as well as taking a beautiful finish for show. It will outperform pretty much any of the old standby carbon blade steels. Only some tool steels will outperform it but IMO not make a better knife for hunting and everyday use.

Anything that will outperform XHP will be extremely hard to resharpen and in fact I use a heat treat and draw tempering process to bring my knives down to around 60 rc with XHP and have a personal knife of mine that tested 59 that started as a test knife and it has seen extreme abuse and still has its original edge.

I hear many times from old know it alls when looking at one of my stainless knives and they say "no I've got to have a 'high' carbon blade". Well what they don't realize is my stainless knives have much more carbon than the ones they are referring too.

Just to add, the old soft carbon steels are a favorite with many because they sharpen so easy and as a result most people can get a good edge on it.

Super steels like XHP with the right tempering process will take a scary sharp edge and hold it very well. Much better than the old stand by carbon steels. Problem is you have to know what you are doing and if one sees lots and lots of hard use or abuse it may have to be sent back to the knifemaker to sharpen. Most stainless steels and especially ones like XHP are extremely abrasion resistant so as a result it holds and edge well but is hard to sharpen. There is always that trade off and if it does get dull then yes, it takes some doings to get it sharp again but I have never had to do anything more than hit one on some crock sticks unless it's been a knife that saw extreme use and usually abuse.

I know this strays a bit from the OPs point of discussion a bit. But regardless of whether any functional difference remains between carbon vs stainless steels I think there still is a difference aesthetically. In my opinion, no stainless revolver could ever look as good as if it were carbon steel with a deep luster blue (not the cheap bluing you so commonly see these days). I'm not saying stainless revolvers can't look good- I have five stainless Ruger revolvers and I think they look great. But the old Smiths and Colts with the deep bluing are especially admirable.

Edit: I now see this is in the "Non-Firearms Weapons" sub-forum and even more off-topic than I originally thought. I clicked on the thread from the homepage which didn't denote its location. It now makes sense why after all these responses no one mentioned how much better blued revolvers look vs stainless ones.