any one can find a scientific way to test knife quality?

[babymax]

I have read a lot of tests about knife.
but most of all, I feel they are not really that scientific, it more rely on personal feeling and experience.

is there a way to do it more scientific?

or possible someone can bring the knifes to "Consumer reports". let them do the test?

I really like to see their result.

 

[DaveH]

I think the first order of business is to define the characterictics of quality as well as ways to measure it.

or you could just by a sebenza.

 

[not2sharp]

Knives are a simple devices used in complexed ways. I find most of the testing and reviews are completely useless. Wether the knife retains and edge, bends, breaks, or rusts, is a factor of its composition and construction; but, whether these attributes are desirable or undesirable, is completely dependent upon the user, the task, and personal preference. There are at least as many priorities and quality standards as there are users. Go with what works for you is the only real test of quality.

n2s

 

[Dog of War]

I agree, most knife tests are subject to a great deal of bias, and conducted under conditions that are not only non-scientific, but render the results unreproducible and unreliable .... and therefore of dubious value.

Tests found in many magazines are the worst due to the paid advertising.

IMO the best tests I've read are from established posters on the internet, notably Cliff Stamp's work. People frequently disagree with Cliff, but I can't recall anyone ever following through and performing the same work as Cliff does, plus additional tests they think are important, and posting their findings in rebuttal.

Because of the ways knives are actually used in real life and the differences between knife users, I don't feel knife testing can ever really be held to kinds of high standards you would find, for example, testing industrial cutting tools designed for a specific job. Which is OK .... I still prefer reading people's tests and findings, especially when they go into enough detail that you could reproduce the same tests and judge for yourself. That alone gives a level of credibility many knife tests (and reviewers-testers) lack.

 

[DGG]

I have a simple scientific test designed for only one user and two knives.

Get two 50 pound sacks of identical type of potatoes

Sharpen each knife.

Get a timer.

Peel and cutup one sack of potatoes, recording the time it takes to do this.

Wait a week (in case your hand/wrist is now sore from the first peeling/cutting).

Peel and cutup the second sack of potatoes with the second knife, recording the time.

Shortest time wins. This scientific test determines which is the best knife for peeling and cutting up a 50 pounds sack of spuds.

This scientific test will not only measure blade performance but also handle ergonomics. And you will really get a feeling for how each knife works.

Thoughts?

 

[Andy_CN]

I have read a lot of tests about knife.
but most of all, I feel they are not really that scientific, it more rely on personal feeling and experience.

As different people use their knives for different tasks in different situations
the best knife (scientifically determined, if possible) could be only average or
even not suitable for the requirements of some people.

There's not the best knife.
It depends on the specific requirements of the person who is using the knife.

 

[Cliff Stamp]

I have read a lot of tests about knife.
but most of all, I feel they are not really that scientific, it more rely on personal feeling and experience.

To do something in a scientific way means you learn from it, it produced meaningful information. Lots of people do such work and share it freely. Mike Swaim did a lot regarding issues such as examining cutting/chopping ability, edge retention and corrosion resistance. In particular he looked how mass, length and balance effected chopping ability and how edge angle and grit finish influenced cutting ability and edge retention.

Alvin Johnston generated a lot of such work by making knives and having them evaluated by professionals. His findings on edge retention and sharpness have been confirmed by the work of Verhoeven and Landes who did funded studies on such issues, looking at how the size of the carbides in a steel effected the sharpess/edge retention and the influence of hardness. Mark Henry of Furi has done similar work. There are also quite a number of people (outside the US) who have published research on the cutting ability and edge retention of knives. Landes gave a list of research papers here awhile ago.

Joe Talmadge expanded on Mike's work in regards to cutting ability with a series of articles on how to specifically modify knives to improve cutting performance and edge retention and ease of sharpening. Joe and Steve both did a great deal regarding the stability of liner locks in regards to torques and impacts. Jeff Clark has studied sharpness in great detail and has learned how to maximize sharpness. Possum has recently been working on ideas of knife balance in regards to performance, specifically power, speed and precision.

There are lots of other posters, I am bound to leave out a few, but off the top of my head; Dave has shown the effect a microbevel and finishes have on cutting ability, Sodak has done work on showing the limits of steels in regards to acute angles, Thom has done similar as well as looked at durability in more extremes with different steels, frank k has done work on edge retention and corrosion resistance, kel_aa has also recently started doing work showing how even very inexpensive knives can be very functional which shatters a number of myths, and Vincent has done similar.

I linked to a lot of the above in the page I wrote about exactly this issue (methods used for knife evaluation) so you can read the origional comments by the above in many cases. I also have a thread running now in the reviews form about how to model the edge retention of knives. Kevin Cashen, Phil Wilson, Wayne Goddard, Jerry Busse, and David Boye have also demonstrated various aspects of performance in a meaningful way. Busse in particular has done live demonstrations and openly invited them to be duplicated by other makers. Cashen is currently championing a cause to make knife makers be more definate in their performance statements by defining benchmarks and ideally have repeatable work so it can be challenged/verified.

There are lot of people doing meaningful work, there is also lots of hype and unfortuantely there is much more hype than facts on most internet forums, however there are some that are high on facts and low on hype, rec.knives for example has a low tolerance for shills and over promotion. It is always very easy to tell which is which even if you don't know anything about the subject. All you have to do is ask a few simple questions. People who are hyping performance will be very vague, they will refuse direct comparisons, they will not want to have their work challenged and they will not guarantee/support any of it.

In general all of the above people are very willing to adapt if you make sensible and meaningful suggestions. So if you see someone doing something which you think could be improved then just tell them so. Realize of course it is in most cases something that the people are doing as a hobby so placing demands on it is kind of ridiculus. So for example when sodak talks about edge durability at low angles I may ask him to see if he can produce a list of steels and angle for a given task, but I am not going to be harshly critical if he doesn't considering he is sharing the information with me for free on his own time.

-Cliff

 

[RealDeal]

Yup, sure fire way, try it and see if you like it, pretty simple really.

 

[Larrin]

The more scientific a test is, the less "real world" it is.

 

[Cliff Stamp]

The more scientific a test is, the less "real world" it is.

This is a gross misunderstanding of what something means to be scientific. The purpose of science is obviously to understand the real world. Doing something in a scientific manner just means you learn from it. It also isn't a binary condition, you can always improve your methods to learn more. If you constrain your lab tests so much that they don't actually correlate well to people using knives then your work is *not* an scientific investigation of those properties obviously. It is a scientific investigation of something, you just have to figure out what.

There is of course no requirement on precision in science. The fundamentals of all modern science were based on work with no computers, very little equipment, no actual labs, nothing at all except the willingness to observe the real world, question what was seen and seek to understand it. That is science. Observe, propose, confirm. If you fail go back to step one. If you succeed then publish and apply for more grant money and rake in all the beautiful women who throw themselves at your feet[*].

The computers, the machines, are just tools, science is in the people and will always been in the people because they have the imagination and sometimes the courage to ask why or propose that everyone is actually wrong and the sun doesn't go around the earth, the earth isn't flat, and yes virgina there is really is a fossil record. Read the books by Feynman to understand why it is very important to sometimes seek "a map of a cat".

When studing something new, unknown and very complex it is often necessary to break it down and simplify. This isn't a good thing, it is just a necessary evil. Some models like the harmonic oscillator are often used simply because the math is easy and they are a decent approximation in many cases and they allow an understanding of the fundamentals. Once you get the basic ideas and more math you move on to more complex models and eventually work with theories and experiments which are quite complex, just like the real world.

-Cliff

 

[Cliff Stamp]

...I can't recall anyone ever following through and performing the same work .... plus additional tests they think are important, and posting their findings in rebuttal.

In general it isn't necessary to do that to propose suggestions on improvement. At one of the first conferences I attended I discussed method with someone who had made a serious study with one of the numerical techniques I was using, Robert le Roy, to be specific. I found out in a very brief conversation that what I was doing was really less than optimal. It wasn't necessary for him to actually redo all my work for me to make his points valid. Of course he didn't demand that I use any of his methods, just pointed out they were better, and offered any assistance he could give if I chose to use his ideas including the full computer code, etc. .

In general you just have to have a bit of a clue and realize that for example when Thom comments that he has had problems with VG-10 at ten degrees isn't sensible to ask him to buy ten random blades and repeat the work, though asking him to resharpen might be. Published science is actually restricted by money and time on a regular basis. Few people are working with no restrictions and in general when you make suggestions or comments on method you always take this into account.

Of course there is a difference between a suggestion for improvement and pointing out a flaw in logic or method which is leading to an incorrect conclusion. So for example if you have someone who is comparing two bowies and who harshly critizes L6 as having a faulty heat treatement because it has inferior edge retention for chopping than 440A it isn't out of line to note that he might get different results if he wasn't in the rain during the chopping and thus he needs to modify his conclusions.

Sometimes we are all in the rain and don't know it. Sometimes people point this out for their amusement and the amusement of others. Sometimes other people offer you a ride. There are too few of the latter and far too many of the former.

Most of the work I do is based on Swaim's, I referenced much of it on my background webpage. If you have not read his posts on rec.knives it is worth doing. He was very quantitative and covered a massive amount of ground. He is still net active, though unfortunately not as interested in knives. But Alvin still is, and still hates stainless, and finally decided to make a "tactical" knife.

-Cliff

 

[Hair]

We can do scientific tests on knife quality when we figure out how to do scientific tests on music quality. Or scientifically prove that Moby Dick is a better book than Animal Farm.

It is subjective.

What is "quality"? How the action is? The fit and finish? Well, how a knife feels to open is very much up to the user. The feel of one knife's action may be perfect for you and horrid to me. What aspects of fit and finish are more important? Yes, you can measure tolerances, but what if one knife has closer tolerances but a more flawed finish? What is more important? Subjective.

Then there is strength and cutting. One knife may have a stronger blade but weaker pivot. Which is stronger? One may slice better but be inferior at chopping. What is the better cutter? Subjective.

Which car is better: A light, fast, great handling, but uncomfortable and loud Lotus Elise? Or a comfortable, practical, easy to drive, but slower and less exciting BMW 7 Series? Subjective. The BMW may have tighter door gaps, but is that the only measure of quality? The Lotus will have better handling dynamics. That may be a more important measure of quality to someone else.

I believe many knife reviws (and many reviews in general) are useless. It does not do anyone any good to say "the knife feels good" or "it cuts well". And if that is what you are annoyed with, I agree. But I think the answer is reviews that describe the knife in a less personal way, rather than trying to use faux-science. Don't tell me it feels good. My hand and my desires are different than yours. Tell me the dimensions of the handle and let me consider how it might feel in my hand. Don't tell me it cuts well. Tell me the angle on the final and primary bevels and let me decide whether they will be appropriate for the kind of cutting I do or not.

I believe reviews are more useful when they are less about telling me if you like the product or not, and more about describing the product so that I can decide whether or not it meets my desires and needs. I believe the best reviews are the ones where you can't even tell whether the person likes the product or not because they simply describe it in a mostly objective way. They may give it a 1/10, or a 10/10, you you cannot tell. And it doesn't matter. Who cares how someone else likes it- If they hate it you still may love it and vice versa. When making a review, personal bias always plays a part, and you will always have to give opinions and be "un-objective" at times. But I don't need to know if you like it or hate it unless I am trying to decide whether to buy you one for Christmas or not.

Don't tell me Knife X has a thin blade, but not too thin. That doesn't tell me anything as "not too thin" to you may be way too thin for me. Tell me how thin it is, or compare it to other knives that I might own or have access to.

Excuse the rant. This comes from many years of being disgusted by the absolutism I see in many reviews. "This is a good movie... better than that movie", "This is a good videogame... better than that other game" etc...

 

[Dog of War]

...I can't recall anyone ever following through and performing the same work as Cliff does, plus additional tests they think are important, and posting their findings in rebuttal.

In general it isn't necessary to do that to propose suggestions on improvement.

I agree completely, Cliff, and I assume you know why I made that remark. I enjoy your reviews, appreciate your sharing your work and have never felt the need to reproduce any of it. Your credibility IMO is very high.

Not having the time or inclination to put in similar effort I can only say "thanks". Even when I tend to disagree with you, I realize your opinions are probably much more objective and empirically-based than mine .... besides, being selfish like I am, I'd rather leave your time free to do more testing and reviews that I get to enjoy, rather than trying to argue something when I know you've got the stronger hand.

 

[Cliff Stamp]

We can do scientific tests on knife quality when we figure out how to do scientific tests on music quality. Or scientifically prove that Moby Dick is a better book than Animal Farm.

There is actual scientific work on exactly these types of subjects. Work has been done for example to determine what pattern is common to songs which become very popular and are "hits". There is a large amount of work on what makes physical beauty, starting of course with Da Vinci's proportions and symmetry. In such cases what is being studied of course is the mass appeal and what are the basic patterns common. This however is very different than evaluating if one knife works better than another at a given task.

What is "quality"?

A knife is a tool designed to perform specific functions, these can be performed and the efficiency measured. It isn't even a very complex tool. Now there is the influence of user variation, specifically skill and experience, but this can be taken into account as well, in the most broad sense it would just be used as a statistical sample. This is how much work studying ergonomics for example is done, actual "real world" evaluations by people "in the field".

There is also the case that different people may want different things. For some people it may be critically important that the knife have very little blade play, so much so they will reject a knife if it fails that criteria irregardless of how it does in all other aspects. This is why it would be useful to people when they are saying why a knife is better or superior to say what they are using for their evaluation, what are the criteria and how are they judging them. Of course any relevant proportions, dimensions and issues of mass distribution would be informative.

None of this means of course that Bladeforums should not welcome someone who just wants to talk subjectively about knives. If someone really just wants to talk about how great a knife is and how much they love it in a completely subjective way then that is cool. If you don't find that useful then just don't read it. Most people however are open to being a little more quantitive if you just ask. However if you critize and demand then they don't, but that is just being ridiculus anyway.

-Cliff

 

[not2sharp]

A knife is a tool designed to perform specific functions, these can be performed and the efficiency measured.

Cliff,

Can you elaborate on what that specific function might be? I suspect that most of those who produce knives today, produce knives in the style of "X", rather then tools intended for a specific purpose. If it were otherwise the makers would come clear on what their tool is supposed to do and whom that tool was intended for. It is not like we market knives with little tags that read:

Grip size 4-1/2 inch, A2 steel (maintain dry, wipe clean immediately after use) for meat and soft tissue cutting at room temperature. Recommended ceramic edge touch-ups after each man hour use; return to factory authorized service center after 40 hours for a edge rebuild.

n2s

 

[Cliff Stamp]

Ask the maker, those that make knives with performance in mind obviously have a set goal because without this defined there is no way for the knives to evolve and all such makers are trying always to make "better" knives. Ask Phil Wilson what one of his fillet knives is designed to do and he will tell you in great detail what you should expect. R. J. Martin, Kevin Cashen, etc. will all tell you very specifically what they design their knives to do.

Even moving beyond this a user can define their own characteristics and thus rank the performance of a knife for a set of tasks. This doesn't then comment or make any inferences on the ability of the maker unless it is also confirmed that these are intended goals, however it can still be informative for both the user and everyone else as well. You can for example take a Ratweiler and use it as chef's knife and rank its performance and conclude that it is a inferior/adequate/superior design based on objective criteria.

This doesn't mean that you then conclude that the knife in general or the maker also has such labels attached, to do that you would as noted need to confirm this is included in the critical scope of work and to what extent. There is in fact no requirement in reviews for the reviewer to actually form such conclusions. They can just present the work, or a broad scope and let the read pick out what is of interest and thus decide how the knife ranks on their own personal evaluation matrix.

-Cliff

 

[bbcmat]

I read all the testing I can - try to pick from it info relevant to MY style and type of cutting.

Problem - Cliff (for example)

1) does not have my hand/wrist/finger requirements
2) does not prioritize cutting characteristics the way I do
3) does not have the same reference points on cutting ability (my tools, my experience) or sharpen-ability.

The responsibility lies with ME to use the info available to my best benefit (guesstimate). I’m thankful for a place to find info, and for the effort of those who are will to test and publish it. I don’t expect to be given the “one big answer” when it comes to cutting tools.

MAT

 

[Cliff Stamp]

1) does not have my hand/wrist/finger requirements
2) does not prioritize cutting characteristics the way I do
3) does not have the same reference points on cutting ability (my tools, my experience) or sharpen-ability.

Physical skill / method is an influence and it would be worthwhile to model along with knife characteristics, this isn't impossible or even difficult you just need the information. In some cases the connection is quite simple for example such the size of an axe head and the users physical strength. In order cases it is harder because methods changes, not everyone swings a knife the same for example so one person can get different dynamic cutting ability than another. This again isn't an impossibility to deal with, you just need information on the method.

Ranking of characteristics is only important if the reviewer wants to actually promote or degrade an item. This isn't even necessary in a review, and if it is there it can be just discussed in detail and thus the reader can use their own criteria to judge the performance. This is no different than how you many any such decisions. You are buying a pair of boots so you ask about durability, insulation, price, customer support, traction, etc. . The guy may have his own ranking and you may have yours but even if they are completely different if he does more than just tell you his final opinion it is worthwhile.

Reference points are one of the biggest problems with many commentaries and why there is often so much contention. You will see people for example promoting strongly the greatness of a certain aspect because what they are comparing it to is actually horrible. Many misconceptions on performance come from this because people evaluate knives with no reference points at all and often performance is promoted as superior when it fact it is just average.

This is why you not only need to use benchmarks you need to define them. If you rank something as average then what is poor and what is exceptional and what else is average? The more knives you discuss in comparison the more likely it is that it will be meaningful because you will hit something that the reader has used, or something at least very similar to it. You can also use tests which don't need any benchmarks as they are definate enough on their own to be meaningful so someone can duplicate them and see how their knives fare.

There are usually issues with random variations in stock materials, but averaging and random sampling will reduce them enough to make the work meaningful.

-Cliff

 

[Suicycoprowler]

I have a simple scientific test designed for only one user and two knives.

Get two 50 pound sacks of identical type of potatoes
............
Peel and cutup one sack of potatoes, recording the time it takes to do this.
............
Thoughts?

Your wife will also be happy that you peeled the potatoes for dinner.

 

[pogo]

I think the USA Military/ Army did a test on knives quite a long time ago. I read the report but, cannot remember specific details on the tests. It had somthing to do with edge turning while whittling Oak I think?