Review : X-Ray Vision from SOG

Cliff Stamp · May 30, 2001

I had intended to do more cutting work with this blade, mainly I was interested in long term lock wear, however the person who it was loaned out to while pleased with its cutting ability and low stress lock stability did not like the low strength in regards to lateral application of force.

After it got damaged during the splitting, which did surprise me, its ability to function as a knife was significant reduced so I just finished up with the durability work. However there is a decent amount of cutting information including the effects of various loads and grits on slicing performance. That aspect will be looked at in more detail later.

Link :

http://www.physics.mun.ca/~sstamp/knives/vision.html

If you do read the above you should also scan through the Recondo review :

http://www.physics.mun.ca/~sstamp/knives/recondo.html

as it contains a significant overlap and more detail on several of the performance comparisions.

-Cliff

[This message has been edited by Cliff Stamp (edited 05-30-2001).]

RH · May 30, 2001

Cliff, Let me say you do a great service to all of us by your testing. I have not seen such thorough testing and reporting even within the pages of Consumer Reports. However, I think you may also be doing manufacturer's like SOG a disservice, by "testing" their products far beyond what anyone would consider normal, reasonable use, seemingly with the sole intent of turning them into scrap metal, and making unfair comparisons part of your test.

Examples:
I think it is unreasonable to attempt to use a Zytel handled folding knife as a prybar or log splitting wedge. And what possible real-world application would be derived from stabbing said folding knife 3/4" inch into wood, then repeatedly smashing it with a pipe and/or leveraging the handle end to cause catastrophic damage to the pivot/lock area?! Subjected to that kind of abuse, Zytel folders made by Spyderco, Cold Steel, Benchmade, et al would meet similiar fates - so what's the point of the test?

I think it is unfair and intellectually dishonest to compare a thin, flat ground fillet knife to a think bladed utility tool and find that the thicker blade is more brittle and prone to shattering. You know as well as I do that thin fillet knives are made with only two purposes in mind - to be very sharp, and to be very flexible. Naturally, a thin, flexible blade will "give", and be better able to absorb the shock of being smashed with a pipe than a rigid, thick utility blade. Again, I fail to see the value of such a test or comparison.

You are a well-respected plank owner here, and I expect to get flames from your supporters, but I think I have some valid points.

Note: I do not work for any knife manufacturers, distributors, or retailers, I'm just a consumer.

Andrew Lynch · May 30, 2001

I see your point, RH, and think that a folder of this construction shouldn't be expected to endure that kind of use unscathed. However, I think that Cliff is just seeing how much punishment the folder (and, indeed any other knife he is testing) will take before being broken or utterly destroyed. That kind of info is useful because then you know how hard you can safely use said blade.

Just because Cliff broke abused and broke it doesn't make it a bad blade (after all, Cliff has broken the best of em'!). I think one has to look at the other tests (edge-holding, ergonomics, etc.) he conducts and look at the review as a whole. Then, you can make your own decision on the quality of said blade.

Cliff Stamp · May 30, 2001

RH:

I think it is unreasonable to attempt to use a Zytel handled folding knife as a prybar or log splitting wedge.

Then you should ignore that part of the review and not draw any conclusions from it.

what possible real-world application would be derived from stabbing said folding knife 3/4" inch into wood, then repeatedly smashing it with a pipe and/or leveraging the handle end to cause catastrophic damage to the pivot/lock area?!

The prying shows how it reacts to lateral forces, mainly where the break points are as well as the order of magnitude of force required for the onset of failure (this is mainly for me as it is difficult for anyone else to judge the amount of force used except in a very rough sense). Prying is an intentional use mainly, except for the odd case in which you made a bad cut in which the material or the blade turns and you put force on it in the wrong way. I have done some work along these lines in meat and bone (stationary and moving) but am hesitant to post such here or even put it up on my webpage as it is quite gruesome, I have done similar with wood (cut into a moving club) and it will put very high forces on the black / lock and handle . Anyway, again if it is something you are not interested in, then ignore it.

The impacts however cannot be avoided if the blade is actually used without extreme care. Accidental impacts off of things you wish you really could have avoided are very common with used materials as they can contain rock and such which will readily impact even the best of blades. As well as just accidental impacts, for example I was doing some chopping recently and the shock bounded the Battle Mirtress off of the platform it was on nearby and it hit into the spine of the PAB and suffered an edge impaction. In regards to gross impacts like the Pipe hits, they are beyond the stress of any cutting use. They would only happen in dire emergencies where you needed to cut something very quickly and had to pound on the blade and/or the blade saw hard contacts in a martial sense. Or accidents such as high drops, I have worked on scaffolding for example 75 feet high. The impacts of a tool dropped from that heights onto concrete is quite high.

Subjected to that kind of abuse, Zytel folders made by Spyderco, Cold Steel, Benchmade, et al would meet similiar fates

That is an interestiong point, based on what I have seen I don't think it is true, but I would not say for sure as it has been too long and I didn't do exactly the same things with some of the other Zytel folders (Cold Steel , Sypderco) I had. But lets just assume it is true. It would then prove that you would not want a Zytel folder to do those kinds of things with.

However consider the blade geometry of the Vision. It has a tanto point for "durability", and sabre grinds which reduce cutting ability in order to gain greater lateral strength as well as fairly thick stock for such a small blade, and finally the 1000 in.lbs lock. What does all this imply about the intended uses of the knife?

If you truely wanted to make a pure cutting tool then use a distal taper on slimmer stock with full height grinds and a slimmer point. The blade on my SAK (Rucksak) for example has similar geometry and it will readily outcut the Vision. The Rucksack will break under even lower lateral force (I have done it a couple of them), and this is expected as they are simply optomized for low stress cutting.

Naturally, a thin, flexible blade will "give", and be better able to absorb the shock of being smashed with a pipe than a rigid, thick utility blade.

That is a good point, however it can't flex in the spine - edge plane and it held up to those stresses fine. As well I recently repeated this with a much larger 440A class blade (10" bolo, 1/4" stock), using a heavier piece of steel for impact, it held up fine. As for the point, it was mainly to show the difference in impact toughness and what you lose to get the wear resistance and strength of the 61+ BG-42.

Such comparisions are very frequent in all the reviews, even the blades that I regard very highly are all outperformed in many aspects either in their reviews directly or when used as baselines for other blades. And yes they are all used in areas that they are not designed to do. Not all are taken to failure for various reasons. Either I didn't own them, or I did and they served a function that I didn't want to lose, or taking them to failure was too difficult.

I think I have some valid points.

One of the most critical being should you do something in a review that evaluates the performance in an area outside of the intended use of the blade? I think so for reasons I have described in detail in the past. Mainly it allows you to get an understanding on what controls the functional durability limits.

A harder question though is who sets the performance limits? If two manufacturers/makers offer similar knives but they have very different claimed upper limits which one do you use when comparing the knives?

If you use the highest one the other blade will most likely get functionally damaged and the people behind it will cry "unfair - that is abuse". if you use the lower limit the people that make the more durable blade get to see a review that doesn't show the strong points of their product.

Andrew :

Just because Cliff broke abused and broke it doesn't make it a bad blade

Yes exactly. Read what was done, and use your own criteria to judge the performance. You also have to factor in any commentary from the maker/manufacturer on if what is described is the intended level of performance.

-Cliff

[This message has been edited by Cliff Stamp (edited 05-30-2001).]

RH · May 31, 2001

Cliff, your points are pointedly well expressed, as I knew they would be, and they are well taken.

I guess the issue I have is that when I subject you reviews to scrutiny, I can say "well, jeez, I would never do all THAT to a knife, so that part is irrelevant to me", which is exactly what you suggest - use the info that applies to you, nevermind the rest. The problem arises when someone looks at your review, just skims over the details of the abuse you gave the subjects, sees the pictures of the destruction, and says "man, what a piece of crap! I won't be buying that knife!", without realizing that your tests go well beyond expected use.

It would be like Consumer Reports printing a story (I'm making this up) about how the GMC Jimmy tips over in turns, without telling you that, by the way, a Jeep, an Explorer, a 4Runner, etc. would also tip over in the same test. Since obviously you don't have the wherewithal to do side-by-side testing, for argument's sake, the Endura, the Voyager, etc. alongside the SOG, just testing the one sample to the limits might unfairly skew someone's purchase decision.

Cliff Stamp · May 30, 2001

RH, yes, someone doesn't evaluate what is done but just make snap judgements on the results of some of the harder work could very well end up with a skewed viewpoint. However I have to decide when I am writing who it is I am writing for. I have chosen not to leave out information that could be misinterpreted by people who chose not to do any critical evaluation as this would lower the information content to those people who will look at the review as a staring point for thought, which is all it is intended to be.

In regards to the isolation, well I can't do anything about that as of this instant. As I get more knives then the results of similar work done with them will be cross-referenced with the work done on the Vision. As well there is nothing stopping people from doing such work themselves and offering up the results here, or asking other manufacturers about how their blades would handle similar tasks and again posting up such information in this thread to put some perspective to the review. As well of course as just seeing what else has already been done. For example :

http://www.jungletraining.com/almar.htm

Some of what Jeff has described, if I was to replicate would involve me using much harder hits than when I was splitting the wood with the Vision. For example :

I severed 2 inch sapling by hammering the blade through with a large stick.

There are lots of woods around there that would make the above very difficult. Pine would not be a problem as its really soft, but beating a knife through a piece of Black Spruce would be fairly difficult. Not to mention :

The next trick was to drive the blade through [the sapling] by beating on the butt of handle.

This is in some respects even worse as now the lock is twisting, torquing and as well as suffering direct impaction.

Of course how hard these things are on the lock depends on how hard you are hitting it. But assuming you wanted to do it in a reasonable amount of hits (like 12) it would take a level of force at least the equal of what I was using on a decent piece of wood, and a lot more on some of the harder, knottier woods.

Damm, now I have made myself too curious. I'll do some work along these lines in the next few days and see if I can't make the above less vague.

-Cliff

A. G. Russell · May 30, 2001

Originally posted by Cliff Stamp:
I had intended to do more cutting work with this blade, mainly I was interested in long term lock wear, however the person who it was loaned out to while pleased with its cutting ability and low stress lock stability did not like the low strength in regards to lateral application of force.

Cliff: I am pretty new to the forums so I hope you will bear with me. I do not mean any disrespect to any one here. I think that most of the people here know that I have been selling quality knives by everybody that makes them for almost 40 years.

Most of you also know that my guarantee is without limit. I have been selling SOG knives since they entered the knife business.

My question is, in all those years, why have I never seen knives from SOG or for that matter from anyone in the knife industry in the condition of these two SOG knives in your reviews?

Will the knives of anyone stand up any better than SOG's did?

A. G. Russell

The General · May 30, 2001

Would a newbee see those pics and think 'its what would happen to any FRN knife'? I doubt it. Interesting tests though. I always enjoy reading your reviews Cliff.

------------------
Wayne.
"To strive to seek to find and not to yield"
Tennyson
Ranger motto

A few useful details on UK laws and some nice reviews!
http://members.aol.com/knivesuk/
Certified steel snob!

Bob S · May 30, 2001

I've been lurking for awhile here in the forums and after reading this review (and a prior review), thought I would finally sign up and make a contribution.

This is my critique of Cliff Stamp's review of the X-ray Vision.

There is some discussion in the last two paragraphs of the "History" section on force and pressure. The statement being made of "how would the lock reacted [sic] to repeated loads of 800 in.lbs of torque."

I printed this review out at a quite robust 17 pages. The writer does not get to his initial subject of the lock until page 12. At that point he does not offer any measurement of force or other scientific type of evaluation but begins to pound on the knife with a 2x4. Further reading shows no relevance to any proper use of any kind of tool, but continues to describe how to destroy just about any useful item. Maybe that should have been the topic of the review.

It's obvious to this reader that Cliff Stamp is totally inept at any kind of scientific evaluation. He should sign up at the nearest college and attend a basic class on scientific methods of testing. As for this report, I give it an "F." It is certainly not worthy of being on a knife forum and articles like this should not be allowed to be put on the website without it being looked at by a knowledgeable monitor. Wannabes who think they are experts are disgusting. The total report is full of garbage and is not worth the powder to blow it to hell.

This obviously took quite a bit of time to beat the knife to death and then write 17 pages about how stupid that was. I thought about writing after I read the last idiotic review by this person but I had better things to do. I wish I had the time to waste doing trivial things but I must continue to be a productive member of society.

Bob

bigbass · May 30, 2001

Bob,

We all appreciate your honesty and welcome to the forums. I'm sorry that you feel so negatively about one of your first experiences here. I just don't think that it is very productive for you to be using such harsh words in your response to get your point across. If you don't like his review then you are entitled to that opinion. If you feel that he is doing a disservice then you should by all means comment but just in maybe in a more constructive manner. I hope that you will continue to post in the forums as you will no doubt get a positive experience. I assure you that Cliff in no way intended to offend anyone, he is just trying to test the limits of these knives which is his right to do so.

[This message has been edited by bigbass (edited 05-30-2001).]

The General · May 30, 2001

While I have disagreed somewhat with Cliff Stamp on some things in the past. I respect that he is one of the FEW here that give actual FACTS and not just say it worked well for me blah blah blah.

------------------
Wayne.
"To strive to seek to find and not to yield"
Tennyson
Ranger motto

A few useful details on UK laws and some nice reviews!
http://members.aol.com/knivesuk/
Certified steel snob!

Bugs3x · May 31, 2001

Despite the obvious heat of Bob S' comments, I think it possible he makes a good point or two.

If my memory were even half-assed good, I could better discuss the sameness of the testing which Cliff reports. I've read several of his reviews, and obviously need to take the time somewhere along the line to read all of them consecutively, or as near so as possible. Anyhow, what I'm trying to say is that the reviews don't seem that similar to each other. There seem to be different ropes used, no explanation as to how the applied pressures in cutting are measured. The sharpening has a wide margin for subjectivy, I believe.

The initial info regarding the claimed length of the blade and the force/weight the lock withstood in testing didn't seem to me to accurately reflect what SOG said in the referred to link.

While I guess I understand the potential usefulness of destroying knives, I can't remember if the methods -- ie bashing a blade with a 2x4 -- have been the same for all the folder reviews I've read. If not, then their validity is questionable. Cliff acknowledges that his SAK would fall apart far more easily than the tested knife, but excuses that by talking about intended purpose.

I guess the main concern I have about the destruction of knives that I perceive to be intended for use in a certain manner, is that the means of destruction are so far removed from that intended use. I guess I can best make my point by using the notion of a folder as a defensive weapon. I read one book on knife fighting which repeatedly referred to knives as "touch" weapons. Another book I just read semi-continuously referred to power thrusts, Power stabs, power power, etc. Certainly most people on the forums seem to value the sharpness of knives. If indeed all the knives I read about are "scary sharp" then to me that places them in the "touch" category. If one is using a sharpened crowbar, then I guess it's "power" may be important.

Nobody wants their knife to just fall apart if in a fight situation the blade strikes bone. But frankly, if a blade can withstand repeated stabs into books and wood to a depth of 3/4 of an inch and then be twisted out without any harm to the point or blade or lock, then I think that knife would probably do just fine if it encountered a rib. I'd really like to know how little force is needed to sink that blade to its hilt in flesh. That would be useful for comparison. I would want blades that sank as easily as possible, with also the assurance of reasonable strength/rigigity. If all I can muster at a point in a fight is a feeble poke, then I'd sure like that to do some damage. I wouldn't want a knife that required all my power on my best day to get it in to the hilt.

I guess what I'd like to see Cliff do, is to take knives that advertise themselves for similar duties, and put them side by side and learn how much either or all can take. For instance, if one thinks slashing ability is important in a potential combat knife, then do some slashing tests. Cutting rope might provide the answers, but I'm not sure. If the Strider mentioned in this review is so much duller, and requires so much more force to reach significantly shallower depths of material, then it seems to me it isn't nearly so well designed for combat use as the tested knife. Yet, somehow in this test, it seemed to fill the role of paragon of virtue. I know I read a review critical of an unsharpened part of the tanto blade on one. That sure as hell isn't a knife I'd want if all I could manage was a feeble poke.

I guess the biggest "scientific" question about Cliff's reviews that needs to be asked in my mind, is are they consistent from test/review to test/review, and are they repeatable. I know that a basic requirement for valid scientific testing is repeatability. I must say I'm kind of doubtful about that.

------------------
Asi es la vida

Bugs

Steelhed · May 31, 2001

I have read most of Cliff Stamp's tests over the past few months and it seems to me that he tested the SOG Vision and Recondo with somewhat greater vigor than other knives in his tests, and some of his comparisons in these tests seemed less than useful for my purposes. This is only my impression. I have learned a great deal from Mr. Stamps postings, and even made a couple purchases based on his results.

So, what do I think? I think Cliff is right and wrong, like most of us when we take a position based on our experience as human beings. I know some of you firmly believe in objectivity, but I believe objectivity is an extremely rare coin because human imperfection almost always colors what we do and say and write. Cliff is right when he says we should consider the results of his tests from our own perspective interests and needs. He is wrong if he thinks his tests are truly objective in a rigorous scientific sense (Sorry, Cliff, and I could do no better than you if I conducted tests myself).

I will continue to read Cliff Stamp's tests (I hope he continues to conduct them), and take from them what I deem applicable to my interests. It should be no surprise that his posted results anger some and enlighten others. For those of you who are angered by his methodology, you are free to obtain your own version of his tested knives, conduct your tests and post them. The more tests and the more information this produces can only give us all a better picture of how different knives perform.

As for the Vision test, I took the following from his results: SOG's new lock appears to be reasonably strong, probably better than a liner lock. I do not like tanto blades or serrations (personal taste issue, not functionality), so the Vision would not be one of my choices regardless of his test results. I would not expect any of my folders to survive the lateral stresses he applied to the Vision, which only confirms my long held preference for fixed blade knives when the chips are down.

Keep up the work, Cliff. Thanks.

Cliff Stamp · May 31, 2001

A. G. :

why have I never seen knives from
SOG or for that matter from anyone in the knife industry in the condition of
these two SOG knives in your reviews?

I have seen lots of knives damaged as badly as a lot of what I have done. Most people don't go as far with repeated damage as once a blade breaks or loses a large piece out of the edge the functionality is basically zero and it is thrown out. I have a decent collection of such knives though. I think I'll put up a gallery with some commentary.

Bugs3x :

no explanation as to how the applied pressures in cutting are
measured.

For the cord slicing under specific loads, the load is fixed to the end of
the cord (its a standard weight), the knife edge is place under it and then lifted until the
weight is raised off the floor. The knife is then drawn across the cord. The
main source of error here is how the cord is held with the off hand and the
upwards thrust on the draw both of which can increase the tension in the
rope. The cuts are done a minimum of 18 times and the median is used as an
estimator as it is very robust even in the face of problems such as the
above. I could fix the cord in a clamp which reduce some of the variance but I can do multiple cuts with my hand faster and achieve the same result.

The sharpening has a wide margin for subjectivy

A different edge will obviously effect cutting ability as well as
durability and edge retention, you can see this especially in the older reviews. To give the most robust results the work
should be repeated with a complete resharpening of the blades at a minimum
of say three times to estimate the variance in sharpening. Not all aspects of the
work are done to this degree, mainly because of the time it would take. For
example the aggression as influenced by edge finish on the 1/4" poly in the
Vision review contains cutting done with three complete sharpenings at each
finish as well as a check for consistency when I used the 3/8" hemp. However on a chopping test that takes say 10 hours I can't, this is only one part (a specific size and type of wood) of one section of the review. Time obviously imposes limitations on how much I can repeat the work. This is also influenced by comments by other users and makers/manufactures. For example if a blade has a poor showing and I get comments that indicates otherwise I will repeat that to insure that what I have described has not been skewed by sharpening etc. .

if a blade can withstand repeated stabs into books and wood to a
depth of 3/4 of an inch and then be twisted out without any harm to the
point or blade or lock, then I think that knife would probably do just fine
if it encountered a rib

If the target is not moving then yes, if it is then the forces can easily
exceed what was done in the review assuming that you can hold onto the blade
and stabilize it during the shock. I have tested this before and I can hold
onto a knife under far greater impacts than I subjected the Vision to, I
tested it out on various fixed blades under really heavy impacts.

I'd like to see Cliff do, is to take knives that advertise themselves
for similar duties, and put them side by side and learn how much either or
all can take.

Well yes, so would I including with multiple samples of each blade, there is however
an obvious reason why I can't really do this.

the biggest "scientific" question about Cliff's reviews that needs to
be asked in my mind, is are they consistent from test/review to test/review,
and are they repeatable.

Some of them are, the ones that are really tightly controlled for example
like the rope cutting. Some of them vary too much because they depend on my
physical abilities. For example the wood cutting I do, is very consistent
in the short term (one month or so), as the results are compiled over several days the the samples tested for deviation before being compiled into one total result. However over the long term it can change. For example I have significantly increased
my wrist strength in the last 6 months (about double) and thus my ability in
a lot of cutting has made a tremendous jump, the whittling and chopping for
example. There really isn't any easy way to get around this except to
completely avoid any such work and just use measured loads, but that avoids
a lot of biomechanical properties which are very important, but it would
quantify the blade geometry aspects. What I could do is try to scale old results by improvements seen in a stock set of blades, but the changes depend on geometry and it would not be trivial. The only way to get around this would be to update the older work however in most cases I no longer have the blades.

Steelhed :

He is wrong if he thinks his tests are truly objective in a rigorous scientific sense

There are several factors that can influence *what* I do with the various blades. For example I gave the Spyderco Calypso Jr. to a friend when I was finished with it because they were very impressed with its cutting ability and thus it served a valuable purpose to them, more so than the information I could have gained from taking it apart, the same thing holds if the knife performs very well at something I do on a regular basis. For example I would truely like to know how flexible and impact resistant the 10V blade I have is, but I am not willing to pay the $cost and wait time of getting a replacement custom to find out the break points. The opposite is true for the Vision, it was returned to me because of problems with its lateral strength and it did not fit an EDC for me because the blade was not optomized for low stress cutting and the handle/blade attachment not for heavier use. Thus the information I could gain from taking it apart was the most valuable option for me. So yes, in regards to *what* is done, I can and will be influenced by my desires as well as those of others around me. However in regards to how I do what is done and the description of the results, it is completely free of prejudice. The results will not be swayed by my opinion of anyone involved with the knife, nor anything I have said about it in the past.

As for the reviews needing improvement, well yes they do as does everything. A lot of it is not done as rigerous as I would like. They do improve overtime however because of feedback from people working with me with the various methods.

Bob S. :

[regarding the lock failure]

he does not offer any
measurement of force or other scientific type of evaluation

This is true, I will be doing more defined work of this type in the future instead of me just hitting it for example it will be subjected to impacts of a specific kinetic energy with a specific material to insure similar impact times. I will also quantify the impact forces I can generate in a few ways. Of course of primary interest to me, is how the blades stand up to such use as to me what I have done is very well defined as I was there and I know my abilities so I can readily understand the magnitude of the applied forces and the energy of the impacts. For others as I have noted in the above, obviously it is not, something that could be improved. I however don't want to go too far in that respect because I would much rather see what I have done cause other people to do such work, and thus complete the picture. There is little desire to have it viewed as a template for judgement as no additional information can be gained from that.

-Cliff

[This message has been edited by Cliff Stamp (edited 05-31-2001).]

pjenkins00 · May 31, 2001

well, i've read a couple of cliff's reviews, and i have to say i'm impressed with his methods and simply the documentation involved in conducting tests like he does. Most of the reviews i have read here on bfc have been very subjective, and were i to write one i would expect it to be similarly subjective.
I particularly found the tests of serrations vs polished plain edge vs one sharpened with "micro serrations" etc and i think the results will effect the way i think about sharpening knives. In so far as the durability testing is concerned, i find it once again useful to me, not necessarily because i would expect to treat a knife like that, but only because it gives me some idea on what i can depend on the tool for. i see the point however, that it may not be obvious that "Just because Cliff broke abused and broke it doesn't make it a bad blade". However, i would much rather see the results of the testing rather than see them left off for fear of misinturpretation. This post is getting a little long winded, so all in all, keep up the good work cliff; i know i couldn't do it.
Pete

------------------
Pete Jenkins
Lefties unite!

Steelhed · May 31, 2001

Yes, I agree, Cliff. "What" people test does tend to be highly heuristic (sorry, I'm a refugee from the philosophy and science forums), "how" people conduct an experiment tends to be more controlled and objective. As far as achieving true rigor, you appear to be constantly upgrading your methodology to eliminate subjective variables. I'm certain limited resources become a barrier to the elimination of all variables (is that even possible?). I have also noted your use of a consistent control (the Sorg D2 custom) which helps me quite a bit.

I guess if I were to start out on my own conducting tests of the type you do, I would first establish a baseline, i.e., I would choose a specific (heuristics again) set of criteria - a blade length, a blade thickness, a profile and edge geometry and then have several blades made according to these specs using different steels and non steel alloys, even perhaps having some blades of the same material heat treated to different RC levels. Then I would establish a specific set of experiments using calibrated machinery to exert the forces in the tests. Once I had the baseline I could then substitute other blade designs to compare against the control. Of course this is a perfect world scenario, and I do not have the resources to conduct tests of this type. I don't know anyone but a manufacturer who might.

I don't know if you've seen the Fallkniven test on their website, but that appears to be a fairly rigorous test, and since they are only testing one of their knives against another of their knives, I would think the results would not be slanted. Anyway, a long winded reply for me to simply reiterate, in the absence of a perfect world, I will continue to read and learn from your tests.

Gator97 · May 31, 2001

Originally posted by Bob S:

I've been lurking for awhile here in the forums and after reading this review (and a prior review), thought I would finally sign up and make a contribution.
Considering overall tone of your post #1, U'd better not

I printed this review out at a quite robust 17 pages. The writer does not get to his initial subject of the lock until page 12.
Cliff is as much of a writer as U are a of a critique. However unlike you Cliff does watch his mouth and the terminology used in his messages and reviews equally. Which isn't that bad at some point, wouldn't U agree?

He should sign up at the nearest college and attend a basic class on scientific methods of testing.

Last time I've checked there were no classes regarding knife testing, but anyways.
And where sould U be going to learn to be a little bit polite, back to kindergarden?

[/B]I wish I had the time to waste doing trivial things[/B]
Me too

But alas...

but I must continue to be a productive member of society.
Sorry to disappoint, but your message wasn't even close... Well, depends on the point of view.

------------------
zvis.com
Have Fun,
Alligator

[This message has been edited by Gator97 (edited 05-31-2001).]

johnniet · Jun 1, 2001

Bob S sounds like a troll to me. Such a long diatribe, followed by saying he has to be a productive member of society--and of course it was his first post.
Who might be behind this? VG? Does Cliff have any humorous "rivals" on the Forums?

Cliff Stamp · Jun 1, 2001

pjenkins:

the tests of serrations vs polished plain edge vs one sharpened with "micro serrations"

That was probably the most interesting aspect to me. One of the things I would like to look at later on is the slicing aggression of similar grit finishes but with different hone materials. I am thinking of Japanese Waterstones vs DMT hones vs Spyderco Ceramics. In particular, I am interested if the 2000 grit DMT hones will allow greater aggression than the other two at a similar high level of polish.

Steelhed :

you appear
to be constantly upgrading your methodology to eliminate subjective variables

Yes, this in an evolution of sorts. I want to find a balance between keeping the work simple enough so that the results are readily understandable, but at the same time rigerous enough for comparisions. I was talking to an engineer yesterday about the review and we discussed several very straightforward ways to put some numbers on several of the things that were done with not a lot of precision so the next time you see a folder review the breaks will be done a little differently.

I would choose a specific (heuristics again) set of
criteria - a blade length, a blade thickness, a profile and edge geometry and then
have several blades made according to these specs using different steels and non steel
alloys, even perhaps having some blades of the same material heat treated to different
RC levels. Then I would establish a specific set of experiments using calibrated
machinery to exert the forces in the tests. Once I had the baseline I could then
substitute other blade designs to compare against the control.

Yes, that would be very nice to do indeed. For example for the past few days I have been looking at the cutting ability of two bowies on light work. One of them is readily outperforming the other, the interesting part is trying to figure out why. The hard part is because they are not at all alike. It would be great instead of that one bowie (the other is a standard baseline) if I had several from the maker that were different in one aspect so I could quantify the effect that each aspect makes. However as you noted, practical considerations do make this impossible, so you have to work with what you have.

In regards to the 440A class bolo I mentioned in the above post, I did some impact work with it yesterday. I stuck it in the same plank I knocked the Recondo out of but upgraded the impact tool from the light steel tube to an 8 lbs maul (the tube was far to light to do anything to the Bolo). With the maul swinging from the shoulder I knocked the blade out of the plank and drove it about 25 feet across the yard. I repeated this a few more times. I then pounded the bolo into an oak log about 12" in diameter and golf'ed it a similar distance. I then pounded it into the same log until it was that far that I knew it could not then break out of it as the force to split the log would be too great, and hit it just above the break point. The tip finally gave way :

http://www.physics.mun.ca/~sstamp/images/cheap_bolo.jpg

The break structure was about the worst I have seen, no surprise considering that the knife sells for about $20 :

http://www.physics.mun.ca/~sstamp/images/cheap_bolo_face.jpg

Considering the very poor heat treat and the
insane amount of stress this knife has seen it was fairly impressive to me what it took to break it. I would be curious to know how a similar NIB blade would react if heated treated with care or what influence a stress relief would have had to the results.

To anyone curious, the notches in the blade were from chopping that one into another exactly like it. The partial tang I broke off both blades, one chopping on hardwoods and the other splitting some knotty wood.

-Cliff

[This message has been edited by Cliff Stamp (edited 06-01-2001).]

Steelhed · Jun 1, 2001

Very interesting results with the bolo. I have a suggestion. Right now, Cliff, you are using your arm(s) to propell either a length of pipe, board, or mallet in your lateral stress tests. It would seem a relatively easy and inexpensive task to fashion a pendulum device out of wood, line, and weights to more easily quantify the amount of lateral force applied to each blade. You could then vary the angle (height of initial release), and the weights to increase the amount of force used to strike the blade. You could then calculate this force in grams or pounds for direct comparisons. The blade (pounded into wood, or held in a vise) could be hit on the side or on the edge to determine strength and/or toughness. This would eliminate the variables of arm(s) fatigue or an overzealous swing made to compensate for fatigue. I've done some tests along this line with a baseball bat and softball (during my player days) and there is considerable variation in applied force (as opposed to perceived force) as the result of fatigue and adrenaline. This would also help eliminate the perception that you are wacking one maker's blade harder than another's.

I understand the need for tests of this type, even if they destroy the test blade, and there is a considerable difference between a slowly applied force (slow bend) as opposed to a striking force, either single or repeated to the point of failure.

Again this is all easy for me to say, but you do the most comprehensive tests I've seen to date, and you indicate a desire to place objectivity above all else, in so much as you can. I have some other ideas for taking the "human" out of the equation, but I'll save them for later post, if you are interested. Thanks.