Curious, why bother with a cutting test with *insert brand name knife here*?

Duane Sanders said:
The human element and variables is exactly what a knife needs to be tested for. Yes the test tells you what a steel will do at a hardness but it doesn't throw in random staples into the cardboard being rammed into at full force. It don't tell you what happens when a box full of something metal right under the cardboard will do. When you get that inevitable swipe into the concrete. When you have flaps glued down so hard you need to pry it apart. Them are the things tests will not tell you. Ask anyone who has worked around any amount of cardboard. All of them will tell you about multiple staple hits in a day, concrete accidentally contacted, fiberglass reinforced tape, hard metal object in a box the tip will contact. Exactly everything you need a cardboard cutting knife to endure. From what I've seen the high wear resistant steels will chip like crazy and you won't be happy you spent so much on them. Cardboard cuts easy. Anything you can rip with your hands is not much of a test for a knife. Yeah, it's abrasive but it is still not tough. A thin dull very tough knife will still cut it easily where a harder more wear resistant steel will chip on variables and the cardboard itself. In every case I've seen the trade off to wear resistance is toughness.

Yes one does better in a no variable human factorless test, but them variables are what defines what you look for a knife to work through for a work knife. Even if you have to touch it up at the end of the day. Atleast there is an edge to sharpen instead of a chipped out damaged one.
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Worked around cardboard for half of my life in the Grocery business.

Dealt with it with a lot of different things over time from jiffy cutters, safety cutters to all sorts of knives in different steels.

A thin dull very tough knife will still cut it easily where a harder more wear resistant steel will chip on variables and the cardboard itself. In every case I've seen the trade off to wear resistance is toughness.
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I don't agree because dull is just well....... dull.... And have only seen a few very small chips (contacting hard steel), more rolls here and there.

I found that s30v had done more and lasted long enough for me doing that type of real work. I might have had to touch it up like once a week stropping the edge a few times for the most part. I kept it at a pretty high level of sharpness, phonebook paper cutting sharp or it was touch up.

Not so sure about ripping triple wall and better cardboard by hand..... Can hardly bend some of that stuff and pretty much stand on it without it bending.
 
Ankerson said:
Worked around cardboard for half of my life in the Grocery business.

Dealt with it with a lot of different things over time from jiffy cutters, safety cutters to all sorts of knives in different steels.



I don't agree because dull is just well....... dull.... And have only seen a few very small chips (contacting hard steel), more rolls here and there.

I found that s30v had done more and lasted long enough for me doing that type of real work. I might have had to touch it up like once a week stropping the edge a few times for the most part. I kept it at a pretty high level of sharpness, phonebook paper cutting sharp or it was touch up.

Not so sure about ripping triple wall and better cardboard by hand..... Can hardly bend some of that stuff and pretty much stand on it without it bending.
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Maybe I'm doing it wrong but I can't ever get by with just stropping an edge back to hair popping sharpness, along the entire edge anyway. I usually leave streaks and scrapes on the strop due to the rolled and dented edges. I may be able to straighten the edge with a stone first but that kind of edge dulls really quickly. So I usually just hit the stones and strop to polish a little and remove the burr.

I was just thinking about that earlier. How easy it must be to just lightly strop every once in a while to maintain sharpness. I need to get to pretty hard steels to counteract those rolls and dents and then I'm left with wear resistance or toughness as an option. I guess I'd rather have toughness because of the crap I do with knives. Hardness without brittleness is the overriding concern for me though. All the other things like impact toughness, wear resistance, corrosion resistance, etc. are just nice to have.
 
bodog said:
Maybe I'm doing it wrong but I can't ever get by with just stropping an edge back to hair popping sharpness, along the entire edge anyway. I usually leave streaks and scrapes on the strop due to the rolled and dented edges. I may be able to straighten the edge with a stone first but that kind of edge dulls really quickly. So I usually just hit the stones and strop to polish a little and remove the burr.

I was just thinking about that earlier. How easy it must be to just lightly strop every once in a while to maintain sharpness. I need to get to pretty hard steels to counteract those rolls and dents and then I'm left with wear resistance or toughness as an option. I guess I'd rather have toughness because of the crap I do with knives. Hardness without brittleness is the overriding concern for me though. All the other things like impact toughness, wear resistance, corrosion resistance, etc. are just nice to have.
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You have a different job than most and the things you cut aren't actually in the norm.

I think something like CPM 4V in the .015" to .025" range would be fine for what you do.

Spyderco has a 4V Mule team available now.

http://www.spyderco.com/catalog/details.php?product=948
 
Ankerson said:
You have a different job than most and the things you cut aren't actually in the norm.

I think something like CPM 4V in the .015" to .025" range would be fine for what you do.

Spyderco has a 4V Mule team available now.

http://www.spyderco.com/catalog/details.php?product=948
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I totally agree. Maybe .015" Behind the edge with an 18-20 dps edge leading up to around .15" at the spine. I really need to learn how to properly convex an edge, too. I think that'd help a lot. You think 63 RC would be too brittle with that steel if done right at the heat treaters?
 
bodog said:
I totally agree. Maybe .015" with an 18-20 dps edge. I really need to learn how to properly convex an edge. I think that'd help a lot.
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That won't help at all.... They are vastly over rated....

Start at 18 DPS and work to 20 DPS until you don't see that damage anymore.
 
Ankerson said:
That won't help at all.... They are vastly over rated....

Start at 18 DPS and work to 20 DPS until you don't see that damage anymore.
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Around 18 works pretty well on the ZT 0180 I've been carrying but I think it's probably a little too thick behind the edge. Thinning the shoulders while increasing the angle a little I think would give me better performance.
 
bodog said:
Around 18 works pretty well on the ZT 0180 I've been carrying but I think it's probably a little too thick behind the edge. Thinning the shoulders while increasing the angle a little I think would give me better performance.
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You could get it reground to around .020" or less behind the edge and go with an 18 DPS edge.

That would be the best thing to do.

Or get a MT 21 in CPM 4V....
 
Ankerson said:
You could get it reground to around .020" or less behind the edge and go with an 18 DPS edge.

That would be the best thing to do.

Or get a MT 21 in CPM 4V....
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Lol. I might be moving again here pretty soon. Trying to save some money and you aren't helping, sir. Though that is the mule I've been waiting for since it was announced awhile back.
 
bodog said:
Lol. I might be moving again here pretty soon. Trying to save some money and you aren't helping, sir. Though that is the mule I've been waiting for since it was announced awhile back.
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$69 ain't bad for that.... ;)

Need to snap one up because after that is gone it will be customs and they will cost MORE.
 
OK I guess I'm lost. What is it we are talking about here? Sharpness on an objective scale or a subjective scale, maintaining sharpness, best angle for original sharpness, best angle to maintain sharpness, best type of steel for original sharpness, best type of steel to maintain sharpness, how to measure sharpness, defining sharpness based on the object to be cut or what?
 
Vinifera said:
OK I guess I'm lost. What is it we are talking about here? Sharpness on an objective scale or a subjective scale, maintaining sharpness, best angle for original sharpness, best angle to maintain sharpness, best type of steel for original sharpness, best type of steel to maintain sharpness, sharpness depending on the medium to be cut or what?
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Hey man, you can't corner us :)

It started off about cutting paper as a means of testing sharpness. How it got to the very cool MT21 is beyond me.
 
Does 4v have any relation to 440v? im to lazy to check around figured Jim would know..
 
to answer my own question, no... significantly different composition. I do want to try 4v though,, but not so interested in 440v (s60v)
 
Duane Sanders said:
The human element and variables is exactly what a knife needs to be tested for. Yes the test tells you what a steel will do at a hardness but it doesn't throw in random staples into the cardboard being rammed into at full force..
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In order to get accurate data about a steel edge holding you have to isolate as many variables as possible. If you do not, your test is totally meaningless. There are many ways to test for toughness, edge holding, lateral strength, tip strength, etc. To try to do them all at once gives you data with so many variables that it cannot be duplicated or compared to anything and you are back to square one.

Duane Sanders said:
It don't tell you what happens when a box full of something metal right under the cardboard will do. When you get that inevitable swipe into the concrete. When you have flaps glued down so hard you need to pry it apart. Them are the things tests will not tell you. Ask anyone who has worked around any amount of cardboard. All of them will tell you about multiple staple hits in a day, concrete accidentally contacted, fiberglass reinforced tape, hard metal object in a box the tip will contact. .
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You just made my point above. You can isolate many of the items you mention into individual tests. All of them being done at once, tells you nothing. You can chop staples, concrete, tape, nails etc. But you do it separately to get data that can be duplicated by others using other knives. Doing it all at once is meaningless.

Duane Sanders said:
Exactly everything you need a cardboard cutting knife to endure. From what I've seen the high wear resistant steels will chip like crazy and you won't be happy you spent so much on them. Cardboard cuts easy. Anything you can rip with your hands is not much of a test for a knife. Yeah, it's abrasive but it is still not tough. A thin dull very tough knife will still cut it easily where a harder more wear resistant steel will chip on variables and the cardboard itself. .
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The whole point of cutting something that takes a bit of time to blunt your knife is to get measurable data. Cardboard actually blunts steel much faster than rope but you can still cut lots of it and get measurable results. Not sure you understand what it means to try to get quantifiable data.

Duane Sanders said:
In every case I've seen the trade off to wear resistance is toughness.

Yes one does better in a no variable human factorless test, but them variables are what defines what you look for a knife to work through for a work knife. Even if you have to touch it up at the end of the day. Atleast there is an edge to sharpen instead of a chipped out damaged one.
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On this we agree.
 
Cobalt said:
The whole point of cutting something that takes a bit of time to blunt your knife is to get measurable data. Cardboard actually blunts steel much faster than rope but you can still cut lots of it and get measurable results. Not sure you understand what it means to try to get quantifiable data.
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Rope isn't a good test media. A blade that has a hard time on rope on a cutting board will easily cut it if something is hanging from it or is holding something together tightly. Same for folding it over a blade and pushing it through. A thick, as sharp as it can be blade that's too thick behind the edge won't do it as easily as a thin more dull one. I've experienced that many times. The rope under tension with the thick behind the edge steel that has a hard time cutting rope folded over it will pop it quick on something tied up tight.

A butter knife will cut cardboard, won't be much help on rope. The best blade for cardboard is a titanium blade carbidized on one side. It will not dull, it actually gets more sharp as you cut. Make it 1/16" thick and watch it go and go and go and be extremely sharp at the end of the day. Other than slicing fruits and vegetables it is good for nothing else. Does the same on rope because it's not really that hard to cut as long as the blade is thin enough.
 
One thing that cutting paper, especially thin paper, is it shows me how smooth my edge is and shows if I have any flat spots along the edge. If the edge won't slice through the paper all along the blade or catches at spots, I can go back and touch up that area and re-strop the edge and try again. I just sharpened a thick knife that I can tell wouldn't be good at cutting vegetable matter like potatoes or carrots but it cleanly sliced thin paper and shaved hair great. Probable be okay for a skinning knife, I doubt you could break it.
 
Duane Sanders said:
Rope isn't a good test media. A blade that has a hard time on rope on a cutting board will easily cut it if something is hanging from it or is holding something together tightly. Same for folding it over a blade and pushing it through. A thick, as sharp as it can be blade that's too thick behind the edge won't do it as easily as a thin more dull one. I've experienced that many times. The rope under tension with the thick behind the edge steel that has a hard time cutting rope folded over it will pop it quick on something tied up tight.

A butter knife will cut cardboard, won't be much help on rope. The best blade for cardboard is a titanium blade carbidized on one side. It will not dull, it actually gets more sharp as you cut. Make it 1/16" thick and watch it go and go and go and be extremely sharp at the end of the day. Other than slicing fruits and vegetables it is good for nothing else. Does the same on rope because it's not really that hard to cut as long as the blade is thin enough.
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I agree for the most part with your first paragraph. I cannot verify your data on the second part talking about titanium. As for a butter knife, yes absolutely. A thin knife can cut brittle strands of hemp rope even when it's dull, but it requires a lot of force. Hence why machetes do so well when swung hard. However, on cardboard you can tell when even a dull knife blunts, as it crushes more than it does cut.
 
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