Stainless & Carbon comparable at the same RC hardness?

[Jamesh Bond]

I tend to sway away from the majority of knife knuts.

I like simple stainless steel (xCr13MoV, 420J2, aus8, etc.) and simple carbon steel for my blades. Usually not a huge fan of anything I need special abrasives to sharpen.

These steels hold a highly functional edge long enough (more so than the descriptions I constantly see online would have one believe), and it's simply a breeze to keep em that way. On anything. Since I constantly maintain my blades, I don't need super edge holding. I honestly don't even understand why that particular trait is so highly regarded anyway. A knife user should be able to maintain said tool, in my opinion.

It's very clear that marketing and bias come into play with steels, clouding our perceptions.

The advantage of carbon over stainless that you hear most often is that higher carbon equals higher hardness. BUT if a low carbon stainless gets to 58 or so (as they often do), and carbon blades are often tempered around 58 for durability anyway, then how much does it really affect the final blade performance? Isn't that "high hardness" wasted at that point?

I know there are a ton of variables I'm not considering. I know that everyone's opinions and uses differ. I know I may not be fully informed here. I also know someone will find an error with my examples. So keep in mind that they are just that:
Examples.

So....
The official question:

At the same hardness, say 57RC, what makes, say 1080, superior to, say 5Cr13MoV???

This question applies to fine grained steels. Therefore, carbon alloys, tool steels, and high carbide stainless are not relevant here.

What are your thoughts?
Thx!

 

[Cobalt]

while I can't speak to the steels you mentioned, I can speak to 1095 and 440C. At the same(similar) hardness, my 440C blades held an edge much longer than 1095. But that is likely due to the alloying elements in 440C. Certainly increased wear resistance makes a difference in a higher alloyed steel than a simple carbon steel.

 

[Lapedog]

I tend to sway away from the majority of knife knuts.

I like simple stainless steel (xCr13MoV, 420J2, aus8, etc.) and simple carbon steel for my blades. Usually not a huge fan of anything I need special abrasives to sharpen.

These steels hold a highly functional edge long enough (more so than the descriptions I constantly see online would have one believe), and it's simply a breeze to keep em that way. On anything. Since I constantly maintain my blades, I don't need super edge holding. I honestly don't even understand why that particular trait is so highly regarded anyway. A knife user should be able to maintain said tool, in my opinion.

It's very clear that marketing and bias come into play with steels, clouding our perceptions.

The advantage of carbon over stainless that you hear most often is that higher carbon equals higher hardness. BUT if a low carbon stainless gets to 58 or so (as they often do), and carbon blades are often tempered around 58 for durability anyway, then how much does it really affect the final blade performance? Isn't that "high hardness" wasted at that point?

I know there are a ton of variables I'm not considering. I know that everyone's opinions and uses differ. I know I may not be fully informed here. I also know someone will find an error with my examples. So keep in mind that they are just that:
Examples.

So....
The official question:

At the same hardness, say 57RC, what makes, say 1080, superior to, say 5Cr13MoV???

This question applies to fine grained steels. Therefore, carbon alloys, tool steels, and high carbide stainless are not relevant here.

What are your thoughts?
Thx!

For some reason carbon steel blades seem to just be easier to sharpen. The other day I was sharpening my Tops BOB and went to test the edge thinking I would check the progresss. Wouldn’t you know it the edge had already gotten razor sharp.

For a long time people thought that stainless wasn’t appropriate for a high quality knives. Advances in technology have made stainless knives a great option.

Also I am going to say that super steels only take more time to sharpen if you let them get dull. Just touch them up at the end of the work day as you would any “not super” steel. It will only take 5-10 minutes. Just like sharpening aus 8 from dull only takes 5-10 minutes. The beauty of super steels is that at the end of the day you come home with a still fairly sharp blade that will only take a moment to touch up. At the end of the day with aus 8 you are sharpening from dull. Just don’t let your super steels get dull, that is the real joy in using them. (For me anyway)

Many people treat their super steels like they do their more basic steels. Letting them get fairly dull before touching up. This is where those 8 hour sharpening sessions come in, don’t let them get dull. Rather once you get a good edge on your super steel once just keep it touched up.

 

[Hickory n steel]

Im with you on like the easier to maintain steels.

I can't help with your question though because I haven't noticed too much sharpening difference between my stainless and carbon steels, however all of the steels are from different companies so how would I know it's the steel itself and not who treated it ?

Stainless steel just gets all scratched up and may eventually look fugly, while carbon steel develops a beautiful patina.

 

[knarfeng]

I like simple stainless steel (xCr13MoV, 420J2, aus8, etc.) and simple carbon steel for my blades. Usually not a huge fan of anything I need special abrasives to sharpen.

So....
The official question:

At the same hardness, say 57RC, what makes, say 1080, superior to, say 5Cr13MoV???

This question applies to fine grained steels. Therefore, carbon alloys, tool steels, and high carbide stainless are not relevant here.

What are your thoughts?
Thx!

Depends on what you are doing with the knife.
At a given hardness 1080 will be tougher than 5Cr13MoV aka 420HC, but the edge retention will be about the same.

So, if you wanted a pocket knife for fine cutting, you would see no difference in performance. But if you wanted a big rough duty knife, the 1080 would perform better.

I do admit to having to fuss a tad more with stainless to remove the final wire edge, but that's a minimal difference.

 

[115Italian]

I think you might be comparing apples to oranges. I think theres more science behind carbon steel and adding carbon to stainless steel. Ive never seen a carbon steel blade thats harder than stainless. But “harder” might be used differently as in the stainless would snap in half and the carbon steel would bend. Typical steel is hard but so it concrete or glass. One bends the others breaks.
Im not really answering your question sorry.

 

[Insipid Moniker]

Apologies, but from what I'm reading the premise of your question is faulty. High carbon content certainly allows a steel to be run harder, but stainless steels have loads of carbon in them as well. Heck, the highest carbon content in a steel I know of is ZDP-189, which is a stainless.

The advantages of carbon that I most often hear quoted are toughness and ease of sharpening, but to get into any kind of in depth answer to the question of advantages and edge retention we're probably gonna have to talk about specific steels. Given the general classification of steels you've specified I would honestly expect the stainless steels to maintain an edge for longer given the same hardness, as they'll have higher carbide content.

 

[DocJD]

In applications where toughness is critical , like throwing or big , long chopping knives and machetes , I'm still a bit leery of stainless . Most failures are due to improper heat treatment . I never had a problem in medium sized fixed or my huge folders from Cold Steel in AUS8 or " San Mai" even with some fairly hard use .

Back in the '80's , I had an expensive Al Mar Pathfinder ( stainless machete / sword) break completely off at the hilt and go flying off into the woods ! That's the kind of catastrophic failure that most concerns me .

 

[Alberta Ed]

I enjoy carbon steels for their ease of sharpening, the way they will take an ultra sharp edge (fewer carbides is the reason, I suspect) and their toughness. But the new(er) super steels, or powdered steels, with their more complex composition offer better edge holding and rust resistance at the price of more difficult sharpening that requires diamond hones.

 

[NJBillK]

A bit off topic, but if you want some different alloys that is likely to be appreciated by you, try AEB-L, and Sandvik 12c27, 13c26 (essentially the same as AEB-L), and 14c28.

 

[Gaston444]

while I can't speak to the steels you mentioned, I can speak to 1095 and 440C. At the same(similar) hardness, my 440C blades held an edge much longer than 1095. But that is likely due to the alloying elements in 440C. Certainly increased wear resistance makes a difference in a higher alloyed steel than a simple carbon steel.

A fair assessment I wish I'd see more often. Hardly anyone ever says this. Even Randall spread disinformation and say their 0-1 has "10%" better edge holding than their own 440. I doubt this is true.

That being said, I did see 5160 hold an edge better than a 440C custom, but it was clear by that point something was wrong with the 440C, and this proved to be the case later on, as it really didn't behave right.

"Good" 440 stainless is definitely unpleasant to sharpen, often with a tenacious wire edge near the end of a re-profile, and flip flopping a few times when you try to put in a micro-bevel. This is serious enough that Carbons like 5160 may be on par for a sharpening time vs time of use ratio. The one I have found that seems to bridge the gap is the lowly 420J often seen on Chinese and Taiwan knives: It is easier to sharpen, and does not seem to give up a lot of edge holding doing this, especially for chopping uses on large knives. This has been so apparent that I'm not sure now, if given the choice, that I would not go for 420 as an absolute first choice on a large knife. I did hear of 420 Bucks breaking fairly easily from dumb things like throwing, so those are definitely tempered a bit brittle, but throwing is misuse anyway.

It's always on a case by case basis, but I no longer look down on 420 at all, and I have seen much more awful results from 440C than 420, even from the best makers: 440 is apparently very easy to screw up horribly, according to Jay Fisher. 420 almost bridges the gap of ease of sharpening towards carbon.

Gaston

 

[Gaston444]

In applications where toughness is critical , like throwing or big , long chopping knives and machetes , I'm still a bit leery of stainless . Most failures are due to improper heat treatment . I never had a problem in medium sized fixed or my huge folders from Cold Steel in AUS8 or " San Mai" even with some fairly hard use .

Back in the '80's , I had an expensive Al Mar Pathfinder ( stainless machete / sword) break completely off at the hilt and go flying off into the woods ! That's the kind of catastrophic failure that most concerns me .

Good grief: Today those can go for $2k on Ebay... Old Al Mar prices are absolutely crazy these days. I'd be very interested to know how that break happened. Just regular chopping use? I just knew the odd thin 5/32" stock could not be trusted in stainless, but that is a frighteningly expensive lesson... Yikes!

Gaston

 

[DocJD]

Good grief: Today those can go for $2k on Ebay... Old Al Mar prices are absolutely crazy these days. I'd be very interested to know how that break happened. Just regular chopping use? I just knew the odd thin 5/32" stock could not be trusted in stainless, but that is a frighteningly expensive lesson... Yikes!

Gaston

Just a few minutes of regular chopping on green hardwood saplings . Al Mar replaced it but I never bought from them again . I suspect it was a bad heat treat . But on my 2nd Pathfinder , the handle became loose fairly quickly and it seems to have only one central pin . So of course it acts like an axle , tending to rotate around that point of attachment . The blade hasn't broken , but I don't use it much . I have very cheap machetes I trust and use more . I paid whatever the wholesale price was in the early 80's . Still it was too much .

 

[ATJ999]

A bit off topic, but if you want some different alloys that is likely to be appreciated by you, try AEB-L, and Sandvik 12c27, 13c26 (essentially the same as AEB-L), and 14c28.

I agree! Well heat treated Aeb L with good blade geometry is VERY hard to beat if you are looking for a stainless that is very user friendly, tough, gets razor sharp with ease, and corrosion resistant. I find it so easy to sharpen and strop. To touch up takes less than 5 minutes freehand, for a really good touch up.
14C28N is another great one. Real steel is a production company that does a very good HT using it.
If you are making a knife, Aeb L is really well priced, and if done right is a great performer. It is also very easy to work with prior to HT, and post HT. Nitro V is a new nitrogen version of Aeb L. Tough stuff. I have a machete in it and it takes a hit like a champ.
More on topic. Some people say Aeb L is similar to a stainless version of 52100. But, they perform differently at different hardness' and different HT protocols. You have to Ht simple carbon steels differently than simple stainless steels, but when done correctly, you can get both to perform VERY well. Aeb L really does not perform well at lower hardness. At 60HRC, it is very tough, and still very user friendly, with good edge stability too.

 

[Gaston444]

(In reply to DocJD) :Too bad... Such a good looking design, usually with a great-seeming nylon sheath.

I tend to avoid recurves, so that is another reason why I never splurged on it.

All the Al Mars I owned (except for the magnificent Shadow IV) had strange, sometimes completely un-ergonomic, often hugely oversized handle shapes (their SOG-style finger-grooved 7" fighter being especially monstrous, truly beyond belief when seen in person). Some also had very poor grind symmetry, despite the Seki origin: I had two that really looked like seconds.

On the Pathfinder, it looks like the grip is too deep near the guard to easily stay in the hand. I know rubber is easily carved, but the shorter Quest looked better in that area.

Gaston

 

[tim37a]

I only make knives out of stainless. M390, and S35VN for skinners, boat knives, and any knife that has to keep a sharp edge for a long time. I sharpen mine once a year and touch them up with a ceramic rod as required, usually about once a month. I can sharpen them on my Edge Pro in about 5 minutes and 3 or 4 strokes on the ceramic rod to remove the wire edge. IMHO, they are not hard to sharpen at all. I am switching to Nitro V for kitchen cutlery because I can use it at Rc 63 or 64. That puts them in the same class as the best Japanese knives. I don't expect them to be any harder to sharpen than the S35VN. Time will tell, however.

 

[DeadboxHero]

The official question:

At the same hardness, say 57RC, what makes, say 1080, superior to, say 5Cr13MoV???


What are your thoughts?
Thx!

Superior at what? Everything? You have to be more specific for a great answer. Toughness? Sharpening? Wear resistance?
There are ranges of different microstructures at the same HRC
Depends on what you want.

 

[DeadboxHero]

I only make knives out of stainless. M390, and S35VN for skinners, boat knives, and any knife that has to keep a sharp edge for a long time. I sharpen mine once a year and touch them up with a ceramic rod as required, usually about once a month. I can sharpen them on my Edge Pro in about 5 minutes and 3 or 4 strokes on the ceramic rod to remove the wire edge. IMHO, they are not hard to sharpen at all. I am switching to Nitro V for kitchen cutlery because I can use it at Rc 63 or 64. That puts them in the same class as the best Japanese knives. I don't expect them to be any harder to sharpen than the S35VN. Time will tell, however.

Nice, do you do your own heat treatment or send out for Nitro V?

 

[tim37a]

I send everything to Peters. I'm too old to waste the time learning to HT. Brad can hit whatever hardness I want right on the money. I have been getting the S35VN at Rc60 and the M390 at Rc 60 but I'm thinking about increasing the M390 to RC 61. I'm hoping others who are using M390 on skinners and hunting knives will chime in with their experiences at Rc61.

 

[DeadboxHero]

I send everything to Peters. I'm too old to waste the time learning to HT. Brad can hit whatever hardness I want right on the money. I have been getting the S35VN at Rc60 and the M390 at Rc 60 but I'm thinking about increasing the M390 to RC 61. I'm hoping others who are using M390 on skinners and hunting knives will chime in with their experiences at Rc61.

Haha Nothing wrong with that man I love Peter's Heat Treatment.
You should definitely put the hardeness higher on m390, that would be rad.