Spyderco Forums

Listen to the people who tell you to pay more attention to sharpening at an angle appropriate to your task.
My brother, who has been more of a steel junky than I for a long time, came up with a methodology for setting edge angles:

• First, take the knife to the thinnest, most acute edge you can stand to grind and use.
• Next, use in real tasks until the edge chips or rolls.
• When the edge chips or rolls, grind off the edge until it's even with no damage remaining.
• Set a new apex at about 2° higher per side than last time.
• Rinse and repeat until you find the right edge for the job and it never chips again.

(He was only half-kidding, he really likes sharpening I think.)

After making a few kitchen knives and giving them to friends, I now know much better why Spyderco's edges are thicker than some of us would like them to be. Some people need a knife to cut through chicken bones, other people need a knife that can survive cutting carrots on top of a ceramic plate.

Well I've seen an H1 blade bent in half that didn't break so I don't think it would be damaged as in chip out but it would roll the edge, also super duper easy to sharpen and gets stupid sharp. Not the best in edge retention. If you only want toughness I'd go H1 or AEBL has really good cut results and you can still get the AEBL urban around I think.

So, a lot of times at work, I've encountered situations where something has to be cut off of something metal - like thick shrink wrap over wire rope, or a plastic cap over a pipe - will any knife steel survive that unscathed, or just use your beater 8cr knife/Stanley box cutter and sharpen out the damage?

Catamount123 wrote: ↑

Fri Mar 06, 2020 8:35 am

One of the things I like about steels like Cruwear, 4V, HAP40 and Vtoku2 is that they are less likely to get dings or chips when accidentally hitting something hard. In your experience, which Spyderco stainless (excluding H1, since I am quite fond of FFG) is most resistant to dings & chips?

The one you don't hit anything hard with, and is sharpened correctly for the jobs at hand.

Yes, that is a serious answer.

Dings are rolls, chips are fractures so you have 2 different issues going on here.... Any steel will either roll or it will chip depending on numerous factors. Once the point of failure is reached based on the variables.

JuPaul wrote: ↑

Fri Mar 06, 2020 2:02 pm

Thought it'd be helpful to actually see Larrin's data here:



Resistance to all types of edge damage would presumably be best in steels that are tougher at higher hardnesses/strength, right? Based on that, AEB-L, Niomax, and Nitro-V would stand out. Of the more readily available steels, CPM-154, m390 and s35vn seem to have decent toughness at higher hardnesses. No data on s90v here, though.

There is actually a very small difference in the steels when we are talking about knife blades, edges.... Much less than most people would think there is.

Blade and edge geometry have much more to do with how the steels will perform than the actual steel type.

That's talking about edge damage..

Now blade toughness... That's a whole different discussion as it's not really related to the topic.

Some people believe they are the same topic, but they really aren't... It is one heck of a lot more complicated than that... Sorry, nothing is really ever that simple nor is it straight forward.

JuPaul wrote: ↑

Fri Mar 06, 2020 2:02 pm

Thought it'd be helpful to actually see Larrin's data here:



Resistance to all types of edge damage would presumably be best in steels that are tougher at higher hardnesses/strength, right? Based on that, AEB-L, Niomax, and Nitro-V would stand out. Of the more readily available steels, CPM-154, m390 and s35vn seem to have decent toughness at higher hardnesses. No data on s90v here, though.

You hit the nail on the head.

Toughness is important, but so is hardness. As you have pointed out, we are talking about edge stability, not just toughness.

Go for ductility. So things like s30v or maxamet will do poorly since they rely on hardness to get by rather than chemical composition. Steels like s35vn, vg-10, m390 (or 20cv/204p) are all ductile, and are much more likely to roll rather than chip. The top of the pile in the regard are Lc200n and 3v in my opinion.

There are also steels that are so well composed they just will microscopically dull out without visual damage, meaning you probably have to reprofile but VERY lightly. High grade super steels like s90v act like this in my experience.

Are we talking avoidance of damage in the first place, or a simple recovery from damage.

The former Is not realistic if you actually use your knife. Surprises happen.

The latter depends (assuming standard factory-edges) on the steel’s fracture-resistance. The higher this metric, the better. Rolls are a nuisance, chips are an existential nightmare.

H1->VG10->LC200N->S30V comprises a continuum, with H1 most fracture-resistant and least wear-resistant (assuming plain-edge), and S30V still comfortably fracture-resistant but with most wear-resistance in this continuum.

I once accidentally dropped my SE Dragonfly Salt onto a hard floor tip-first from countertop height and the very tip bent. Using the SM, I was actually able to straighten the tip without any sign it had ever bent. I would have expected it to at least be weakened from that, but it isn’t.

That said, I did accidentally chip off the very tip of a Tasman Salt SE, when I accidentally bumped the tip into a glass table top while using it. Not much of the tip, just the very tip. That Tasman’s tip is very narrow, so I’m not surprised the very end chipped off, H1 or not. Easily fixed on the SM.

Jim

If you're looking for a steels ability to resist edge deformation of any kind, not just chipping, edge stability and edge strength are more important than toughness.

Edge stability and edge strength are controlled by grain structure, carbide volume, carbide size, and hardness.

Unfortunately, stainless steels do not excel in those areas. Chromium carbides are relatively large, and chromium tends to limit a steels maximum attainable working hardness.

That being said, with targeted heat treat protocols, something AEB-L, SG2, or even the likes of s35vn, m390, or cpm154 could all do well.

Baron Mind wrote: ↑

Sun Aug 09, 2020 3:57 pm

If you're looking for a steels ability to resist edge deformation of any kind, not just chipping, edge stability and edge strength are more important than toughness.

Edge stability and edge strength are controlled by grain structure, carbide volume, carbide size, and hardness.

Unfortunately, stainless steels do not excel in those areas. Chromium carbides are relatively large, and chromium tends to limit a steels maximum attainable working hardness.

That being said, with targeted heat treat protocols, something AEB-L, SG2, or even the likes of s35vn, m390, or cpm154 could all do well.

Actually, not really and this is something I have been saying now for a very long time.

Edge stability is not what people seem to think it is and nor are the reasons for it or what has the real effect on it. Edge geometry and hardness have the most effect on this far beyond what type of steel it is.

All steels will fail one of two ways, they will chip or they will roll once the point of failure is reached.

Chromium carbides actually don't have that much effect on the overall working hardness, a lot of stainless steels have a high working hardness equal to or surpassing some carbon steels. With the PM steels the carbides are kept in check along with different HT protocols that can help refine the grain structure.

In short it really doesn't matter what the steel is as long as the overall design, HT and geometry suit the tasks at hand.

There really isn't that much of a difference in the steels overall when it comes to the edge holding up. The edge is so thin at the apex, the part that really matters here it doesn't matter what the steel is. How it's prepared has much more effect on that overall like I said.

Now if you want to talk about blade strength/toughness for something like choppers, swords etc. that's a whole different topic.

There is a ton of misinformation out there, mostly marketing and urban legends are complete BS.

As long as the knife is sharpened correctly... That's a HUGE ONE... And the edge geometry is set correctly for the task it's fine.

Obviously there are a lot of factors involved and the experts have chimed in with the sciency stuff. My two cents, as far as stainless steels go, S35vn and CTS-XHP have held up the best for me against accidental and harder use damage.

Good corrosion resistance and rolling resistance -> SPY27 (62 HRC assumed)

Great corrosion resistance and chipping resistance -> LC200N (58 HRC assumed)

Fair corrosion resistance, rolling resistance, chipping resistance -> Cru-wear / Z-wear

...

If you have problems with your existing knives, just increase the edge bevel angle. A 10 degree increase in bevel angle will probably have more of an effect than the difference in steel used. I like JacksonKnives approach.

Ankerson wrote: ↑

Sun Aug 09, 2020 4:27 pm

Baron Mind wrote: ↑

Sun Aug 09, 2020 3:57 pm

If you're looking for a steels ability to resist edge deformation of any kind, not just chipping, edge stability and edge strength are more important than toughness.

Edge stability and edge strength are controlled by grain structure, carbide volume, carbide size, and hardness.

Unfortunately, stainless steels do not excel in those areas. Chromium carbides are relatively large, and chromium tends to limit a steels maximum attainable working hardness.

That being said, with targeted heat treat protocols, something AEB-L, SG2, or even the likes of s35vn, m390, or cpm154 could all do well.

Actually, not really and this is something I have been saying now for a very long time.

Edge stability is not what people seem to think it is and nor are the reasons for it or what has the real effect on it. Edge geometry and hardness have the most effect on this far beyond what type of steel it is.

All steels will fail one of two ways, they will chip or they will roll once the point of failure is reached.

Chromium carbides actually don't have that much effect on the overall working hardness, a lot of stainless steels have a high working hardness equal to or surpassing some carbon steels. With the PM steels the carbides are kept in check along with different HT protocols that can help refine the grain structure.

In short it really doesn't matter what the steel is as long as the overall design, HT and geometry suit the tasks at hand.

There really isn't that much of a difference in the steels overall when it comes to the edge holding up. The edge is so thin at the apex, the part that really matters here it doesn't matter what the steel is. How it's prepared has much more effect on that overall like I said.

Now if you want to talk about blade strength/toughness for something like choppers, swords etc. that's a whole different topic.

There is a ton of misinformation out there, mostly marketing and urban legends are complete BS.

As long as the knife is sharpened correctly... That's a HUGE ONE... And the edge geometry is set correctly for the task it's fine.

I'm likely missing something, but it would seem then that the selling of "Super Steel de-jour" is like selling snake oil. The most important part of the blade is in how it is made, not from what it is made of.

JRinFL wrote: ↑

Mon Aug 10, 2020 10:48 am

Ankerson wrote: ↑

Sun Aug 09, 2020 4:27 pm

Baron Mind wrote: ↑

Sun Aug 09, 2020 3:57 pm

If you're looking for a steels ability to resist edge deformation of any kind, not just chipping, edge stability and edge strength are more important than toughness.

Edge stability and edge strength are controlled by grain structure, carbide volume, carbide size, and hardness.

Unfortunately, stainless steels do not excel in those areas. Chromium carbides are relatively large, and chromium tends to limit a steels maximum attainable working hardness.

That being said, with targeted heat treat protocols, something AEB-L, SG2, or even the likes of s35vn, m390, or cpm154 could all do well.

Actually, not really and this is something I have been saying now for a very long time.

Edge stability is not what people seem to think it is and nor are the reasons for it or what has the real effect on it. Edge geometry and hardness have the most effect on this far beyond what type of steel it is.

All steels will fail one of two ways, they will chip or they will roll once the point of failure is reached.

Chromium carbides actually don't have that much effect on the overall working hardness, a lot of stainless steels have a high working hardness equal to or surpassing some carbon steels. With the PM steels the carbides are kept in check along with different HT protocols that can help refine the grain structure.

In short it really doesn't matter what the steel is as long as the overall design, HT and geometry suit the tasks at hand.

There really isn't that much of a difference in the steels overall when it comes to the edge holding up. The edge is so thin at the apex, the part that really matters here it doesn't matter what the steel is. How it's prepared has much more effect on that overall like I said.

Now if you want to talk about blade strength/toughness for something like choppers, swords etc. that's a whole different topic.

There is a ton of misinformation out there, mostly marketing and urban legends are complete BS.

As long as the knife is sharpened correctly... That's a HUGE ONE... And the edge geometry is set correctly for the task it's fine.

I'm likely missing something, but it would seem then that the selling of "Super Steel de-jour" is like selling snake oil. The most important part of the blade is in how it is made, not from what it is made of.

Actually no....

It's this whole edge stability idea has been taken so far out of context and overblown over the years it's to the point that it's nothing more than a joke now. Most of it has been marketing and other assorted "opinions" about it that never have been true from the start.

MOSTLY talking about folders here..... It just doesn't matter... Sharpen the knife correctly for the use that's intended and go with it.

For fixed blades, choppers etc.... Yes, it does matter much more depending. Most of as in almost all fixed blades that are made for harder use are very thick behind the edge. I have personally seen .045" and thicker..... :rolleyes:

"WOW this X knife in Y steel is just awesome, I can do yadda, yadda, yadda"

Well yeah, it's .045" behind the edge... :rolleyes:

NOW, there are fixed blades that are MUCH thinner and still designed for field use, something like .020" to .025" or so.....

Yeah, that's equal to your folder measurements behind the edge for the most part.

And I am not talking about CPM 3V either..... MOST of those are in the .035" or thicker range.....

But then with the fixed blades they see a lot more heavy use so there is also heavier blade stock too normally.


BOTTOM line here is there isn't a one size fits all cookie cutter answer to it.


I would hope people wouldn't take their tomato slicer that's .005" behind the edge and go out and chop down a oak tree with it... Likely wouldn't go very well....


Basic common since plays a big part with knife use, something that tends to be ignored more so than not...

If someone needs to use a knife as a screwdriver grab a butter knife out of the kitchen drawer and leave the folder in their pocket.

Again, sharpening angle and thickness behind the edge are "how it's made" (or modified) and not "what it is made of", so the super steels in a pocket folder are really selling a dream. Like you said, choppers, axes, machetes are all in a different category so I am not including them, only folders. At least that is what I'm taking from your posts. Again, I'm likely missing something.

JRinFL wrote: ↑

Mon Aug 10, 2020 1:15 pm

Again, sharpening angle and thickness behind the edge are "how it's made" (or modified) and not "what it is made of", so the super steels in a pocket folder are really selling a dream. Like you said, choppers, axes, machetes are all in a different category so I am not including them, only folders. At least that is what I'm taking from your posts. Again, I'm likely missing something.

Yeah, edge retention......

Stain resistance.

Not really a lot left as one isn't going to go out and chop down a forest with their 3" folder.

Some steels are easier to sharpen than others for some people, some are more stain resistant than others.

Some hold an edge for longer than others...

So yes having choices is a very good thing.

Ankerson wrote: ↑

Sun Aug 09, 2020 4:27 pm

Baron Mind wrote: ↑

Sun Aug 09, 2020 3:57 pm

If you're looking for a steels ability to resist edge deformation of any kind, not just chipping, edge stability and edge strength are more important than toughness.

Edge stability and edge strength are controlled by grain structure, carbide volume, carbide size, and hardness.

Unfortunately, stainless steels do not excel in those areas. Chromium carbides are relatively large, and chromium tends to limit a steels maximum attainable working hardness.

That being said, with targeted heat treat protocols, something AEB-L, SG2, or even the likes of s35vn, m390, or cpm154 could all do well.

Actually, not really and this is something I have been saying now for a very long time.

Edge stability is not what people seem to think it is and nor are the reasons for it or what has the real effect on it. Edge geometry and hardness have the most effect on this far beyond what type of steel it is.

All steels will fail one of two ways, they will chip or they will roll once the point of failure is reached.

Chromium carbides actually don't have that much effect on the overall working hardness, a lot of stainless steels have a high working hardness equal to or surpassing some carbon steels. With the PM steels the carbides are kept in check along with different HT protocols that can help refine the grain structure.

In short it really doesn't matter what the steel is as long as the overall design, HT and geometry suit the tasks at hand.

There really isn't that much of a difference in the steels overall when it comes to the edge holding up. The edge is so thin at the apex, the part that really matters here it doesn't matter what the steel is. How it's prepared has much more effect on that overall like I said.

Now if you want to talk about blade strength/toughness for something like choppers, swords etc. that's a whole different topic.

There is a ton of misinformation out there, mostly marketing and urban legends are complete BS.

As long as the knife is sharpened correctly... That's a HUGE ONE... And the edge geometry is set correctly for the task it's fine.

I meant to end my post by agreeing with everyone that said edge geometry plays a bigger role in edge stability than steel composition, just as it does in edge retention.

So I agree it is more important, but to say that composition, hardness, carbide size/volume, and grain structure are all of zero importance is
wrong.

I don't feel like going and citing sources on each one of those, but the information is pretty readily available. If you want to argue they do matter, but not enough to make a noticeable difference during certain high speed impacts or something to that effect, fine, that's a reasonable debate. You can say their value has been overhyped, but don't say it's purely hype.

The one article I did dig up was on how chromium limits maximum attainable hardness. I couldn't remember the exact mechanics of it, but I knew I heard it from a reliable source. https://knifesteelnerds.com/2019/12/30/ ... overrated/

I do agree that powdering stainless steel helps to minimize chromium carbide size, and achieve a more even carbide distribution and finer grain structure. I may have overstated the case for low chromium steels in that regard, at least compared to modern powdered stainless steels.

Baron Mind wrote: ↑

Mon Aug 10, 2020 11:02 pm

Ankerson wrote: ↑

Sun Aug 09, 2020 4:27 pm

Baron Mind wrote: ↑

Sun Aug 09, 2020 3:57 pm

If you're looking for a steels ability to resist edge deformation of any kind, not just chipping, edge stability and edge strength are more important than toughness.

Edge stability and edge strength are controlled by grain structure, carbide volume, carbide size, and hardness.

Unfortunately, stainless steels do not excel in those areas. Chromium carbides are relatively large, and chromium tends to limit a steels maximum attainable working hardness.

That being said, with targeted heat treat protocols, something AEB-L, SG2, or even the likes of s35vn, m390, or cpm154 could all do well.

Actually, not really and this is something I have been saying now for a very long time.

Edge stability is not what people seem to think it is and nor are the reasons for it or what has the real effect on it. Edge geometry and hardness have the most effect on this far beyond what type of steel it is.

All steels will fail one of two ways, they will chip or they will roll once the point of failure is reached.

Chromium carbides actually don't have that much effect on the overall working hardness, a lot of stainless steels have a high working hardness equal to or surpassing some carbon steels. With the PM steels the carbides are kept in check along with different HT protocols that can help refine the grain structure.

In short it really doesn't matter what the steel is as long as the overall design, HT and geometry suit the tasks at hand.

There really isn't that much of a difference in the steels overall when it comes to the edge holding up. The edge is so thin at the apex, the part that really matters here it doesn't matter what the steel is. How it's prepared has much more effect on that overall like I said.

Now if you want to talk about blade strength/toughness for something like choppers, swords etc. that's a whole different topic.

There is a ton of misinformation out there, mostly marketing and urban legends are complete BS.

As long as the knife is sharpened correctly... That's a HUGE ONE... And the edge geometry is set correctly for the task it's fine.

I meant to end my post by agreeing with everyone that said edge geometry plays a bigger role in edge stability than steel composition, just as it does in edge retention.

So I agree it is more important, but to say that composition, hardness, carbide size/volume, and grain structure are all of zero importance is
wrong.

I don't feel like going and citing sources on each one of those, but the information is pretty readily available. If you want to argue they do matter, but not enough to make a noticeable difference during certain high speed impacts or something to that effect, fine, that's a reasonable debate. You can say their value has been overhyped, but don't say it's purely hype.

The one article I did dig up was on how chromium limits maximum attainable hardness. I couldn't remember the exact mechanics of it, but I knew I heard it from a reliable source. https://knifesteelnerds.com/2019/12/30/ ... overrated/

I do agree that powdering stainless steel helps to minimize chromium carbide size, and achieve a more even carbide distribution and finer grain structure. I may have overstated the case for low chromium steels in that regard, at least compared to modern powdered stainless steels.

That I didn't say....

Everything does indeed matter...

What I did say was it won't make much of a difference IN FOLDERS..


Sharpen the blade for the tasks at hand and sharpen it correctly.

Keep the use of the said knife within the design parameters. Look at the knife blade and THINK about what you would want to use it for. If it's not made to take the type of use you intend don't use it for that purpose... There are folders on the market that are lets say more forgiving to abuse than others. Thicker blade stock, reinforced tips, heavier construction etc...

Use some common since.

I know it's a novel idea, especially these days, but people do need to take some responsibility for what they do.

So, edge retention is not the same as edge stability? Would it be correct to say material (steel chemistry + HT) is the primary contributor to edge retention while sharpening and geometry are the primary contributors to edge stability?