Request - Steel data provided by model

[kbuzbee]

I know various requests have been made along these lines but with all the "new" steels we are seeing, I wanted to raise the question again. I think this would make an excellent additional set of information to provide for all Spyderco knives. And this is totally in the spirit of "all good, just different" :D

First - I want it by knife. Not a generic number that the steel is capable of but what the design goals of each specific knife are. I would be perfectly happy with a disclaimer "These are the design/mfg goals and individual knives will have slightly greater or lessor values." We all know that factors like heat treating, machining and geometry all impact performance. Knowing this would help people select the blades that appeal most, to them, for their needs.

Second - I'm not talking about chemistry. That is also interesting to know and we've been provided with the comparative table. But I can't look at a table and know what all the impacts of all the included elements are. I can guess that a knife with more chromium is more stain resistant or that a knife with a higher carbon content is harder but this are more assumptions than facts.

So what kinds of things am I taking about?

Hardness
Ease of sharpening
Toughness
Edge holding
Corrosion resistance
Grain size
Suitability to sharpening process
Suitability to task (slicing, chopping etc)

I'm sure the vast majority of this data is already known by Spyderco. Use of comparative numbers would keep the use of this data to compare to other brands to a minimum (which I'm sure Sal would require and I am fine with). Maybe use a 100 point scale? Some of it isn't quantitatively known (but could be). Some things will be different as users change the edge angle of a blade and would differ by the tools available (eg - does the user have a Sharpmaker w/ diamond stones or a soft Arkansas stone ;-). Still, since they are comparative, I would see value.

So how would this be presented? Compare two knives made from steel X. Steel X is known as a very hard steel. Hard to sharpen. Holds an edge forever but forms micro chips.

Knife one is hardened to Rc 65 forming large carbides. This is the way this steel is usually "done".

Knife two is hardened to Rc 60. Using a different quenching process the steel forms much smaller carbides. Is easier to sharpen and tends to roll rather than chip.

Both are 3" FFG but knife 2 is thinner stock.

Looking at the chemical formulation wouldn't tell you any of this but the data tables tell two completely different stories:

Knife 1:
Hardness - 96
Wear resistance - 97
Ease of sharpening - 78 - diamonds recommended
Toughness - 72 - blade may fracture if struck
Edge holding - 94 - edge lasts a long time under normal use but will tend to chip when used to cut harder materials.
Corrosion resistance - 80 - Simple wipe and dry after exposure to water. Food acids may cause staining if not cleaned promptly.
Grain size - 70 - large
Suitability to sharpening process - best sharpened to a coarse edge providing micro serrations
Suitability to task (slicing, chopping etc) - good over all slicer with high lateral strength

Knife 2:
Hardness - 82
Wear resistance - 88
Ease of sharpening - 97- easily sharpened on Arkansas stones
Toughness - 96 - will survive sever impact
Edge holding - 78 - under hard use, will require frequent touch ups. Edge tends to roll when used to cut harder materials
Corrosion resistance - 85 - Simple wipe and dry after exposure to water or food.
Grain size - 92 - very fine
Suitability to sharpening process - takes a very polished edge
Suitability to task (slicing, chopping etc) - excellent over all slicer with moderate lateral strength

Obviously numbers would have to leave room for new materials (or those numbers could go beyond 100 at that point?)

Putting an entry into a sorted database would allow sorting based on any of the given properties for comparison. So if you are looking for a knife that takes the best polished edge you can find it easily. If you are looking for the toughest knife for chopping, you can find it...

Now, I fully realize that ANY modern cutlery steel is beyond the requirements of most of us, most of the time. This is geeky, steel junky stuff but I think it would be both fun and educational.

Obviously, this is just a starting point. Yab may find a blade with an edge holding of 88 actually cuts more drywall than one with a rating of 92. Application specific results but you'd get a general trending.

Anyone else?? Is this beyond the scope of what we should reasonably expect from a "production" knife? What kinds of data would you like to see??

Ken

[ChapmanPreferred]

Interesting idea Ken. I am not sure this would be necesssary for me, but I suppose I would reference the data if it was available.

[Lord vader]

This might be a helpful start.http://www.simplytoolsteel.com/knife-st ... ction.html

[kbuzbee]

This might be a helpful start.http://www.simplytoolsteel.com/knife-st ... ction.html

That is a great site but doesn't target the specifics of how the steel was used in a particular knife. One specific example is the recent ZDP Mule that was "over hardened". One persons over hardened knife is another persons dream blade. Knowing what each knife actually ships with is, to me, a step beyond that excellent article.

Yes, I know, it's over kill but I'm totally into over kill. :D Heck, If I lived closer to Golden I'd go do all the testing and publish the results for free. It's something I think most of us would both value and enjoy...

Ken

[nozh2002]

This question I was asking starting from 2003.

Nobody will tell you - this is sensitive info in knife business and this is why no Spyderco nether Buck no one disclose CATRA test results - even they do tests for different steels and blade geometries. More then this if you try to test it yourself - you will make angry a lot of loyal fans of almost every knife manufacturer, trust me this data is quite not welcomed.

Thanks, Vassili.

[JNewell]

Wouldn't this wind up with a large degree of subjective opinion? (Asking, not asserting)

I know various requests have been made along these lines but with all the "new" steels we are seeing, I wanted to raise the question again. I think this would make an excellent additional set of information to provide for all Spyderco knives. And this is totally in the spirit of "all good, just different" :D

First - I want it by knife. Not a generic number that the steel is capable of but what the design goals of each specific knife are. I would be perfectly happy with a disclaimer "These are the design/mfg goals and individual knives will have slightly greater or lessor values." We all know that factors like heat treating, machining and geometry all impact performance. Knowing this would help people select the blades that appeal most, to them, for their needs.

Second - I'm not talking about chemistry. That is also interesting to know and we've been provided with the comparative table. But I can't look at a table and know what all the impacts of all the included elements are. I can guess that a knife with more chromium is more stain resistant or that a knife with a higher carbon content is harder but this are more assumptions than facts.

So what kinds of things am I taking about?

Hardness
Ease of sharpening
Toughness
Edge holding
Corrosion resistance
Grain size
Suitability to sharpening process
Suitability to task (slicing, chopping etc)

I'm sure the vast majority of this data is already known by Spyderco. Use of comparative numbers would keep the use of this data to compare to other brands to a minimum (which I'm sure Sal would require and I am fine with). Maybe use a 100 point scale? Some of it isn't quantitatively known (but could be). Some things will be different as users change the edge angle of a blade and would differ by the tools available (eg - does the user have a Sharpmaker w/ diamond stones or a soft Arkansas stone ;-). Still, since they are comparative, I would see value.

So how would this be presented? Compare two knives made from steel X. Steel X is known as a very hard steel. Hard to sharpen. Holds an edge forever but forms micro chips.

Knife one is hardened to Rc 65 forming large carbides. This is the way this steel is usually "done".

Knife two is hardened to Rc 60. Using a different quenching process the steel forms much smaller carbides. Is easier to sharpen and tends to roll rather than chip.

Both are 3" FFG but knife 2 is thinner stock.

Looking at the chemical formulation wouldn't tell you any of this but the data tables tell two completely different stories:

Knife 1:
Hardness - 96
Wear resistance - 97
Ease of sharpening - 78 - diamonds recommended
Toughness - 72 - blade may fracture if struck
Edge holding - 94 - edge lasts a long time under normal use but will tend to chip when used to cut harder materials.
Corrosion resistance - 80 - Simple wipe and dry after exposure to water. Food acids may cause staining if not cleaned promptly.
Grain size - 70 - large
Suitability to sharpening process - best sharpened to a coarse edge providing micro serrations
Suitability to task (slicing, chopping etc) - good over all slicer with high lateral strength

Knife 2:
Hardness - 82
Wear resistance - 88
Ease of sharpening - 97- easily sharpened on Arkansas stones
Toughness - 96 - will survive sever impact
Edge holding - 78 - under hard use, will require frequent touch ups. Edge tends to roll when used to cut harder materials
Corrosion resistance - 85 - Simple wipe and dry after exposure to water or food.
Grain size - 92 - very fine
Suitability to sharpening process - takes a very polished edge
Suitability to task (slicing, chopping etc) - excellent over all slicer with moderate lateral strength

Obviously numbers would have to leave room for new materials (or those numbers could go beyond 100 at that point?)

Putting an entry into a sorted database would allow sorting based on any of the given properties for comparison. So if you are looking for a knife that takes the best polished edge you can find it easily. If you are looking for the toughest knife for chopping, you can find it...

Now, I fully realize that ANY modern cutlery steel is beyond the requirements of most of us, most of the time. This is geeky, steel junky stuff but I think it would be both fun and educational.

Obviously, this is just a starting point. Yab may find a blade with an edge holding of 88 actually cuts more drywall than one with a rating of 92. Application specific results but you'd get a general trending.

Anyone else?? Is this beyond the scope of what we should reasonably expect from a "production" knife? What kinds of data would you like to see??

Ken

[kbuzbee]

Nobody will tell you - this is sensitive info in knife business and this is why no Spyderco nether Buck no one disclose CATRA test results - even they do tests for different steels and blade geometries. More then this if you try to test it yourself - you will make angry a lot of loyal fans of almost every knife manufacturer, trust me this data is quite not welcomed.

Thanks, Vassili.

I agree, Vassili, that was exactly why i suggested a relative number scale. Not using industry standard numbers (such as CATRA). I think this would keep the discussion within the Spyderco family of knives and not provide too much information to the competition.

Wouldn't this wind up with a large degree of subjective opinion? (Asking, not asserting)

No, I agree, but it would be, as I said, merely a starting point. Clearly someone with a power grinder will have a different opinion of how difficult a blade is to sharpen than the guy with the Arkansas stones but the "data" would be relative. And someone working around salt water would have a different opinion of corrosion resistance than someone living in Phoenix. Yab slicing dry wall has a different definition of edge retention than I do working in my garden... A lot of it is "opinion" but coming from the factory there would be "some' degree of consistency within the set... Maybe??

Ken

[The Deacon]

Sound like a tremendous amount of work for something that would be of interest to a relatively small number of people. Personally, I rather the folks at Spyderco devote their time and effort to building knives. However Ken, if you're volunteering to buy the knives and the necessary test equipment, perform the tests, build a website, and post the results, I wish you success.

[kbuzbee]

Sound like a tremendous amount of work for something that would be of interest to a relatively small number of people. Personally, I rather the folks at Spyderco devote their time and effort to building knives. However Ken, if you're volunteering to buy the knives and the necessary test equipment, perform the tests, build a website, and post the results, I wish you success.

Thanks Paul, I knew I could count on your support. :D

But seriously, don't you think most of this "testing" is done anyway?? I'm sure an intern could whip it into something functional in a day or two.

Obviously, if the effort were monumental, I too vote for "more knives". But if the data is there.... You know what I mean?

I guess it's a silly idea... Never mind...

Ken

[unit]

Not a silly idea, but difficult, costly, and potentially dangerous to implement.

I say "dangerous" because it would offer up a target for competitors to attack. Not that the world is necessarily a sneaky, devious, or shady place to business, but sometimes offering too much detail about your products results more in customer complaints than satisfaction.

As an example...imagine the complaints a manufacturer would get if it said that knife "A" has an "Ease of sharpening" of 97 (Arkansas stone) and knife "B" is an 78 (diamonds) on the same metric, and some people felt that "B" was actually easier to sharpen in their findings? Suddenly they want to send "B" in for additionally testing because the heat treat "must be wrong" since it sharpened like a softer steel.

I love the idea of having this sort of data, but my experiences with manufacturing taught me that you should share no more data than is absolutely necessary (the same goes with legal matters).

[The Deacon]

I suspect Spyderco shoots for a given hardness range in all blades of a given steel. At least that's what I got out of some of Sal's comments regarding ZDP-189. Assuming that's the case, I'f further suspect they reject any blades that test outside that range. I think it's safe to say that expecting absolute consistency at a specific Rockwell number is unrealistic. Assuming that's true, then ease of sharpening, toughness, and edge holding will probably vary somewhat between blades at the low and high bounds of that range, but should be consistent at any given RC number. Again based on my limited understanding, for any given steel, ccorrosion resistance should be a factor of finish, rather than hardness. I have no idea whether grain size is strictly a function of the steel, or if hardness is a factor, but either way I'd think it would be also be consistent within a fairly narrow range.

Suitability to sharpening process and suitability to task (slicing, chopping etc) are the only things I believe would vary significantly between models in a given steel, but they're also bound to be considerably more subjective than the other parameters. I've heard folks praise the slicing ability of a Military.

[nozh2002]

Thanks Paul, I knew I could count on your support. :D

But seriously, don't you think most of this "testing" is done anyway?? I'm sure an intern could whip it into something functional in a day or two.

Not really - testing is not done anyway. It is very few companies doing testing (Spyderco, Buck and Case) many other just follow certain process hoping that it will work out somehow (and in many cases it does works out - somehow).

Thanks, Vassili.

[kbuzbee]

Again based on my limited understanding, for any given steel, ccorrosion resistance should be a factor of finish, rather than hardness. I have no idea whether grain size is strictly a function of the steel, or if hardness is a factor, but either way I'd think it would be also be consistent within a fairly narrow range.

No expert either, Paul but I would think the heat treating would impact both (as well as the hardness, of course).

Just by example, chromium can be combined into a carbide, impacting hardness, or not, improving corrosion resistance.

Same with grain size. A fast quench will yield smaller, tighter grain where a slow one will give you a larger structure.

But that is all just my (mis?)understanding.

Ken

[Koen Z]

I would pay quite a lot for such info. And Spyderco does pay quite a lot for this info, I believe Sal said there are 6 people at Spyderco who do something with the testing of knives and steels, including Sal and Eric. So I don't think they will ever publicate such info.

If you publicate your info with your relative scale, some smartass will be able to translate these numbers to the real, original numbers.

Nice idea, but I don't think Spyderco or an other company will execute it.