How do you test your knives?

SirSpice said:
Is a durability demonstration the same as destructive testing?
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No. Durability puts something to hard use to see how it fares.
Destructive testing, keeps cranking it on until something breaks, what by definition is meant to destroy.
 
SirSpice said:
Is a durability demonstration the same as destructive testing?
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Knife testing and a durability demonstration are different things.

Knife testing is looking at many things but can be summarized as evaluating the materials the blade and handle are made from and the geometry used to construct them. Is the alloy suitable, is the hardness and microstructure optimal for the application and are the geometries of the blade and handle right?

A durability demonstration demonstrates the abuse a blade can tolerate without breaking, chipping out or taking a bend or the cuts an edge can tolerate and maintain some degree of an edge.

One is used to optimize a knife for an application, the other is used to show folks what a knife can do. There is some overlap but they're different things.



When I'm testing a new alloy, a new heat treat or a new blade or edge geometry I like to compare it to known good works that I used as comparative standards. To answer the question, how do I test? Specifically I'll carve some pressure treated pine, chop that same pine, carve divots from some specific hardwood (osage orange), chop that hardwood, carve slivers from a nail and chop that nail, looking that the edge under bright light and magnification after each cut and comparing it to a known good standard run through the same media at the same time under the same conditions. I'm looking for failure mode (chipping, rolling, denting) and severity of that failure compared against other known standards. I learn a lot about the effect of edge angle, bevel thickness and angle, hardness and the difference between different kinds of microstructures you create in your heat treat. I have a good Rockwell hardness tester and I can control the geometry such as thickness behind the edge and the edge angle with great precision which has allowed me to dive deeper into other aspects of alloy, geometry and heat treat tweaks using nothing more that repeatable cut media and cut processes and a flashlight and a magnifying glass. It isn't rocket science dialing in a process if you control your variables. It is interesting to find two pieces of steel from the same bar in identical geometry and the same rockwell hardness have different properties depending on their condition going into heat treat, their heat treat and the processes that follow it. There are differences to be found and meaningful and repeatable differences can be measured. This is how I test my work, but not how I demonstrate it.

A demonstration needs to provide proof that your works will hold up like you say it can in a way that can be documented on a computer screen, not a microscope. Since a lot of my work focuses on edge retention in rough use I'll show a sharp edge in paper then scrape and chop a dirty 2X4 then cut that paper again, then chop a nail and a cinder block than cut some cardboard. This proves the work holds an edge in rough use but not at the expense of tolerating abuse. It's easy to cut a cinder block without breaking a knife if the knife is thick and relatively soft. But doing that with something that is thin enough to peal thin layers from a tomato and can bend 45 degrees and spring back straight but will still hammer through a concrete paver demonstrates your work is dialed in to a degree beyond what most people are familiar with. This is a meaningful demonstration, though it isn't how you test your work in development. They're both meaningful and legitimate but they are different things. And in my opinion it isn't hype or showmanship to do this, it is a valid demonstration of your work and a meaningful display of its abilities for someone judging it.

Obviously there is more to a good knife than this and not everyone is as focused on certain attributes but unless someone is primarily focused on "art knives" I think that most folks should be testing and demonstrating their work to at least to some degree.
 
nmbarta said:
ancientsteels,
Tips were the whole point of the original post, I'll take any I can get.
As of today, I need both hands to count how many knives I've made. I'll assume you have a few blades on me!!
I haven't done enough to have anything to base an opinion on, but I'll keep my opinion that good custom knives are better knives.
I assumed that "good" and "custom" went hand in hand, live and learn.
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I have only made 4 blades in 2 years of work (lack of tools) but as far as practical experience i have some that most don't in that using primitive tools i have still managed to craft knives.

For a good San-Mai i recommend a high carbon (1085-195) edge and either 15n20 or spring steel spine,(other smiths please chime in if I missed something or you have better combos). Basically a San-Mai is made by making a sandwich of three plates of steel.

Think of your mild steel as the bread and your high carbon as the cheese. You want to make sure that all three are approximately the same width and length and weld all four sides air-tight, bring the billet to about 1800-1900 degrees and forge weld it all together by hammering and or pressing the billet. when you do your grind later you will end up grinding off the bead that initially held the three pieces toghether, (again if someone else has more input, or if I missed something please chime in).

Once you have all three welded together, and your basic shape go through with your quench.
grind and refine the finished product to where you want it.
When you grind in the edge you will grind away the mild steel from the edge and have a high carbon edge that is strong, sharp, and reliable, and a mild steel spine that will absorb impact and be very durable.

I recommend an acid etch once you have your edge ground so it brings out the Hamon line, it makes it look super cool!

I have not yet made a San-Mai, but I know the process fairly well.
The other smiths on here will probably know some stuff I don't ( I have gone to them for advice several times) so feel free to ask anything.
We try to be helpful and friendly.

If I missed something, any one who caught it please let me know.

I cant watch youtube because my internet is too slow so I dont know if this video is any good, but I hope it helps.

www.youtube.com/watch?v=bzOPySQie7g

And these other links should help. Usually I have trouble finding information on-line about Blade-smithing/blacksmithing, and it took me about 30 mins just to find these.
But any way I hope it gives you a better result. It is the same technique that is used in making traditional Katanas and that is why they are still a highly sought after sword amongst sword enthusiasts.

https://en.wikipedia.org/wiki/San_Mai

https://koboldpress.com/real-steel-san-mai/


None of us can know everything, but as a group we have a wealth of knowledge.
Hope all of this helps, and I wish you all the luck in the world.
Have fun, be safe, and best wishes.
 
Just for clarification.....A San mai lamination line is not a “Hamon”.

Nathan, your comments are always informative.
 
samuraistuart said:
Just for clarification.....A San mai lamination line is not a “Hamon”.

Nathan, your comments are always informative.
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The Hamon line is the line that differentiates on a knife or sword the hard edge from the softer spine, Usually in differential hardening
After an acid etch, the high carbon edge is a darker gray, and the the mild steel when polished is bright and mirror like. It is the line that these two create in a San-Mai that is the lamination line.
Thanks for the clarification.
http://www.ksky.ne.jp/~sumie99/hamon.html
 
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samuraistuart said:
Just for clarification.....A San mai lamination line is not a “Hamon”.

Nathan, your comments are always informative.
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You are correct in what you say. A true Hamon is created by differential hardening. However in colloquial terms and for the purposes of quick understanding and relaying of information, the lamination line of San-Mai steel is sometimes referred to as a Hamon line.

It is simply an easily understood term and best suited the message I was trying to covey.

But you are correct, and I mean no disrespect or offense in my previous posts.
As always I never assume to know everything. and I appreciate the clarification.
Often times I have difficulty finding the correct word or phrase to convey my meaning, and therefore resort to commonly understood terms that come as close to what I mean as possible.
I apologize for that. I am not illiterate, simply have trouble picking the right term sometimes.

Wishing you the best!
 
I have edited some of my previous posts to be more accurate. Thanks again for the clarification samuraistuart!
 
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Nathan the Machinist,

Thank you, that is exactly what I was hoping for.
I'd love to own one of your knives. You clearly take a lot of pride in what you do, and not just what you can make a knife look like, but what you can make a knife do. That is much more important to me.


Rick Marchand,

"Not just a knife", you guys are awesome at explaining what I was trying to get at in the first place.
Being new to this, and only having made a few blades, I wanted to go right to testing my work. Fit and finish is going to take some time, but I wont' waste my time on that until I can make a capable blade. That's why I'm using para cord handles for now, they work for what I need at the moment and cost about a dollar to make.
I probably didn't go about it right, but I do know that this knife can take a pretty good beating and keep on cutting.
I'll get better, so will my testing, and so will my knives.
When I can make a blade that I'm happy with, I'll start spending more time on how I'd like them to look.
Looks are nothing without performance to me.

I'm really happy to hear that there are knife makers here that believe in their products and their abilities to make a knife that isn't just pretty.
 
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ancientsteels,

As little as I know about all of this, I was fortunate enough to work with a very well know knife maker almost twenty years ago.
I've always had an interest in this, just not the time for it.
I didn't learn anything about building knives, and very little about HT , but I did get to learn about making damascus, mosaic damascus, powdered steel mosaic dmascus, and few combinations of all of them.
I hope to have the tools to properly forge weld at some point, but I'm not there yet.
A forge weld is easy to do, a flawless forge weld is not easy at all and requires more tools than I currently have.
I still have the two billets of damascus that I made with him that I got in payment for helping. 1 1/2"x 1/4"x 12" roughly, they are beautiful, hopefully I'll get to the point where I feel confident enough to hammer and grind on them, I've been looking at them for a long time.
 
You have been very eloquent in presenting your opinions, so, why in your grande finale to your thread do you cherry pick one, out of context quote (read sound bite) and not put forward the whole thought stated? The entire thought directly expresses the value of testing, and when it is appropriate, and beneficial to your process.
Do NOT take a frustration with knife dweebs as my mantra for my knifemaking philosophy, in an attempt to elevate yourself into some holier-than-thou plane if existance you don't deserve.
Had my say, done with it.
 
nmbarta... I think you are painting with too broad a brush in some respects and not a large enough one in other areas.
nmbarta said:
I'm really happy to hear that there are knife makers here that believe in their products and their abilities to make a knife that isn't just pretty.
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You have to realize that a line like this is going to insult people. I don't agree with the logic behind this statement, either. We seem to share the same need for what I consider extreme testing... but I would never be so close minded to assert that those who choose not to abuse their knives don't have the same level of sincerity in making a functional knife. An argument could be made that they are more grounded in reality. Just something to consider.


Dan... I think you are over-reacting to nmbarta's personal opinions. Be secure in you own conclusions and the fact that others will be like minded.

Let's not get out of hand with the digs, guys.
 
Rick, got it, but respectfully disagree. This is a public forum that anyone anywhere can read. THAT speaks to the uneducated reading something taken out of context and drawing an erroneous conclusion that maker XXX doesn't do 'due diligence', and therefore makes crap. THAT speaks to professional reputation, not an insecurity.
But I will play nice in de sand box.
 
So far all of the testing "I've done" is to hand my hunting, fishing, and farming buddies a knife to keep and use in the field. So far the only one I've done any rework on is one of my earliest knives mostly to clean it up after being left in his shop after cleaning around 100 fish and not cleaning the blade for a couple months so it had a good bit of corrosion. I also thinned the bevels down quite a bit like my later knives knowing the steel would hold up going thinner behind the edge.
 
DanF said:
Rick, got it, but respectfully disagree.
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That is a valid point... "insecurity" was the wrong word. IMO, its almost impossible to avoid being misquoted. Whether intentional or not, is going to happen. All we can do is try our best to explain ourselves. I would hope that folks truly interested in the subject would read the entire thread. I know that is asking a lot.. lol. I agree with you pointing out nmbarta's wrongful assertion. I just saw the progression going South and wanted to keep it to the facts rather than what I felt was passive aggression. Perhaps I read it wrong.... I am Canadian... sorry.
 
I make small little slicers for the cowboy/rancher world. I'm big into real life testing. This is the fall out of your pocket and run over it with the lawnmower test:

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Second big cowboy test is losing it in the corrals and having it be buried in cow manure for several months.

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For budding knife makers this is also an excellent way of taking a pretty nice piece of ironwood and making it look like rather plain walnut. Just in case your heavy on the ironwood and short on the plain walnut.

I've also experimented with the lose the knife and let the cowdog find it and use the mammoth ivory handle as a chew toy for several months test. But I don't have any pics to share of that one, so I can't really recommend it.

Nathan Nathan the Machinist Nathan the Machinist is an eloquent man as well as a man of refined and discriminating taste. He see's one pic of my wife cowboyin' and thinks she "super hot". An opinion we both share.

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DanF
I didn't mean to offend, I was simply quoting the obvious difference in how some people view a knife.
I removed that part from my previous post. That's part of the problem with with forums, there's no tone of voice, and without being careful, one can come across in very unintended way. My bad.
You are correct that these forums can have any effect on someone's business. Because of this thread, I know some makers I would buy from and some that I wouldn't.
DanF said:
Every time I see, or hear about some knife torture test I just shake my head.
Do people also do some kind of random 'see how much it can take', tests to all the tools they buy?
Getting ready for your JS or MS test, that's fine, but other than that, it's a fricking knife, treat it with respect, take care of it and it'll take care of the task it was designed for.
This, more than anything else is why I hate FiF.
If you're new to knifemaking, I guess I can see '''pushing it to the limit', to make sure your process is good to go. Other than that, like they said ^^^.
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I obviously offended you before you joined the thread simply by testing my knife. Then you get offended and insult me for quoting you "out of text"? Well, there's the whole quote, hopefully your not offended by your own words.

You started out by basically making a mockery of what I just did in my HT/test process, and didn't add then didn't add anything productive to the thread. I can see laughing at a new guy a bit for doing something silly that doesn't make sense, then maybe giving him a few pointers, but that's not what you did. You came into this thread with a bad attitude to begin with, and ended up offended. That's not on me.
The original question was about a camp knife and how I went about HT it and testing it. You hate a TV show, because I did a test on a knife and then asked for opinions from professionals on how I went about it? That doesn't make sense to me. Seems like this was a good thread for you just skip over and move on to subjects that aren't so offensive to you.

Good luck with all that you do.





Rick Marchand said:
You got the right place... just different schools of thought.

I tested my knives to destruction(sheaths too!). 62lbs of scrap, to be exact... I weighed the buckets years after. My mentor told me it was silly. I am an admitted serial knife abuser and I make knives for ME, so not only do I need to know what they can do, I need to know what they can't do.

I make tools, not just knives in the traditional sense. If a client wants a blade they can dig in the dirt with and bust open tree stumps for mealworms, it better damn well do it. That is still a knife but it's no longer just a knife.

I understand folks can be quick to judge and expect other to agree with their well thought out philosophies but we are all different and that's what makes it such a cool craft.
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There have been two very different views of custom knives and knife making expressed by several custom knife makers in this thread. It's easy enough to read.
I'm not trying to come across as holier-than-thou, I think it's pretty obvious how I feel about knives and what they're capable of, and I know I have a long way to go before I'll be satisfied with my abilities.
I'll continue to perform these tests to know how much they can take. As ridiculous as that may seem to some, it's information that I want to have about the products I'm making.
Thanks to those who've posted productive information to the topic at hand. My testing will change because of it.
I apologize to anyone I may have offended, it wasn't my intention.
 
Horsewright,

That's a great idea! I love the antiqued look.
No need for all of that though, I have plenty of walnut I'd trade you straight across for that ironwood.
I'll add the lawnmower test to my process, it should fit in nicely between throwing it in the gravel and chopping brass rods.
 
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