How tough is your edge really?

richard j said:
stevekelby, what do you think of 1/2" nylon climbing rope? k II can cut it like thread.
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I haven't tried it, will have to get some. I think 550 paracord is another useful test, lots of people cut that often.

Maybe a good compromise would be how much force it takes to cut paracord, 1/2" nylon, manilla rope, push cutting newspaper and half a dozen other things. That could give a comparison of what edge is better for what task.

No edge can split wood and give a good face shave.

You need the right tool for the job, and the right test for the tool.

Wood might be good to show resistance to chipping, but I don't think it's very accurate, especially with such soft woods.
 
i just cut a kevlar glove in half with it and push cut some newspaper right after. i should have sent you a pair of gloves back to play with.
 
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I like where this thread went last night. I am very new to knives, only been into them for the past month or two with any real dedication. I may have been a little off in my first post, but I am glad some of the other guys were able to articulate what i was trying to type.

There really should be a standardized test for edge retention. On modern marvels they showed a kitchen knife company using a machine similar to a press to force their knife down and push cut at the same time through test media.
 
That was a CATRA test. It is a standard test for edge holding of knives. A handful of knife companies have one and use them often, though very few publish any comparative results.

Perhaps no edge can split wood and still give a smooth face shave, but it's a standard feat to chop wood and shave arm hair.
 
David Boye, a knife maker who's also published many books on knife making, says about knife tests: "My criterion for a good performance test is this: does it tell me how a knife will perform in a real life situation?"

There are numerous accounts on the web about his dendritic steel making thousands of cuts of rigging or hemp rope without resharpening, and the sharpening takes only a few strokes on a standard stone to get back to original sharpness.

Murray Carter, 17th generation Yoshimoto bladesmith and ABS mastersmith, talks about cutting rolls of newspaper or rolled magazines and looking at the edges of the paper, including how the ink is displaced on the magazines at the edge of the cut.


I don't really have a dog in this fight other than to say I think the OP's idea of using relatively challenging tasks to evaluate edge retention is a good one... especially if those challenging tasks are relevant to what you want to do with the knife.
 
BostonBull said:
How tough is your edge really?
I have been reading a lot on here lately, TONS of great info! I see a lot of guys say, i cut this many ropes, or this gauge wire, or hit this many 2x4's and MY edge still cuts hair, or still push slices newspaper, or will still cut free hanging news paper hung over the blade.
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Lets find a species on the list that rates at 2000 or higher, Apple, some hickory, dogwood, Osage Orange, etc all rate above 2000. Then let that piece dry out just like they do on the Janka tests, and then hit it with your sharpened edges. After the hitting, does it shave hair? Cut newspaper? Cut a piece of newspaper draped over the blade just by bouncing the knife?
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You are confusing toughness testing with edge retention testing. "Toughness" and "Edge retention" are different properties and are tested by different methods.

  • People who cut rope or cardboard-type media are testing edge retention.
  • People who chop are sometimes testing toughness, but are usually primarily testing other attributes of the knife.
Feel free to chop anything you want with your own knives. You could even address your comments to those who run chopping competitions. But, there are a whale of a lot more people who cut with a knife than people who chop wood with a knife. Leave us cutters out of it.

Carry on.
 
Wolfjohn said:
Why would you want to chop 2x4s with a knife?

Man, I gotta go along with this 100%. Knives are a cutting tool- period. I've seen first hand, people using a Damascus knife to pry open a paint can lid and snap the tip off a $200 plus blade. I find that totally rediculous but, short of giving an a new owner of a blade and IQ test, I guess you just shake your head and shut up because it's their investment.:confused::confused:
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It's one of the tests you must pass for a knife maker to become a Master Smith, so obviously the governing board that decide who is a master in this field see it as a way to judge a knife...you have to cut it, then show it is still shaving sharp, you also do free hanging rope cuts. :) Dunno if that has already been mentioned but figured I would respond with this video too.

[youtube]7JOP3h_ZidY[/youtube]

Kyle Royer detailed this in his youtube channel. :thumbup:
 
knifenut1013 said:
Chopping wood is not really a edge retention test as it is a geometry and impact test.
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I have looked to one of these tests and think, that is one main part of the test. Does it cut easily into the wood? Edge and blade geometry.

nativecajun57 said:
Mr. boston bull I understand exactly what you are saying. These children are just afraid that their precious knives might break or chip the blades if they cut something worthy of testing the edge besides cutting a soft conifer species of wood. I have never saw this level of disrespect mixed with imaturaty on this forum till now. I get what you are saying.
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+1 I was disappointed how ppl. react on this good question. This is a knife forum. You can think, that ppl. are into the basic knife tests and don´t answer loke some did here before. Good that bostonbull was so patiente.

Robert.B said:
It's one of the tests you must pass for a knife maker to become a Master Smith, so obviously the governing board that decide who is a master in this field see it as a way to judge a knife...you have to cut it, then show it is still shaving sharp, you also do free hanging rope cuts. :)
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Exactly. It is a common test.

Well, i know, that cutting, whittling or chopping hard or dryed wood is a terrible thing for an edge. And chopping would be a hard test for the whole blade and man / woman. So, will there be anything learned, except, that any edge will be deformed or damaged and the man or woman will be tired after that or what ever?

Do we have to tell before, wich edges are made to cut hard wood or would anybody think any edge can do that?

Must edge geometry and wood fit together?

Is there an edge geometry right to do this work with less
 
The idea is you have a high enough understanding of steel and how to get it into a state it will pass the tests...you cant just do a backyard job with basic understanding of your steel and expect to pass, I can make knives and have made a few which are great users but I know they wouldn't pass the MS examination. Handle strength, tang design and such all comes into play as well.
 
back in the fall of 09 i let chuckinohio take k II with him to show the southern ohio forge and anvil members. he said one member was into competition cutting and if i remember right, the blade he used was m4. chuck told me after he checked it out, he said he has to make him one like it.

when chuck came up to get the knife, we chopped with it quite a bit and it was never touched up before he left. another member picked it up from him and played with it some more. he was cutting the corners off phone books and comparing it to the busse i convexed for him. he said k II went through the phone book like butter where the busse had trouble even though it was shaving sharp.
he said the edge was still shavign sharp.
 
The Benchmade Osborne Chopper Competition Cutter 171 is made of M4, I've handled one but never got to use it...but videos of it in use at cutting comps it is wild! it tears through everything thrown at it like it wasn't there.

BM171 would be perfect as a woods knife.
 
Why would you want to chop wood with a knife, or cut anything with one? There are axes, hatchets, shears, scissors, box cutters, side and front cutting pliers, circular saws, bow saws, hacksaws, bandsaws, chainsaws, coping saws, jigsaws, scroll saws, tin snips, nibblers, cutoff wheels, oxyacetylene torches, plasma cutters, waterjets, wire edm, scalpels, nail files, letter openers, potato peelers, mandolins, cheese cutters, blenders, keys, fingernails, teeth, and broken glass.
 
Edit: Removed entire reply just made. I thought the beer thing was pointed at me. That does not mean I don't like beer though };~)

cajun.
 
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