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The Newbies Arena Are you new to knife making? Here is all the help you will need. |
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#1
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Knife testing "advice"
I don't much get into the discussion about blade testing for a couple of reasons. One being, I don't think I have enough experience to suggest anything. Another is, like a number of people, I have to decide what I expect in my knives or rather, what I expect out of my knives and find a process that produces that. I use tools as they are intended and thus, have no expectation that my knife should be able to saw through barbed wire or chop through the 6" hard black locust fence post that barbed wire is attached to nor hold an edge while using it to dig a hole in the dirt and rock for that fence post.
So... I see regularly on here, in fact, all the time, the advice to newbies to "break a blade" as a test to look at grain and find out how good your heat treating is. Yet rarely, if ever, have I seen any real information as to why and what to look for or particularly, how to interpret what you see. Oh I know, you want a "fine" grain but fine compared to what? Is fine grain clearly defined or is it subjective? And what if? What if the grain is too, uh, "grainy" or not fine enough? What is one to do about that? And how is a newbie to know how or what to do? Additionally, what are the parameters of a "good" knife or rather, what test(s) does it have to pass to be considered good? Or just okay? Or servicable? Or excellent? How is a newbie to know? Obviously a bit of research into heat treating a particular steel will show that there is some amount of latitude in heat treating process that still results in satisfactory results. So if we heat the blade of ___ steel to between 1450? and 1500? and then quench. Well, what if we don't get anticipated grain structure. How much difference with a change of 15?-40? make? Any? A lot? And then there is also the question of what results are desired to produce a knife that meets X expectation? I've seen people on YouTube hammer their knife through a concrete block to prove....What? That you can drive a piece of steel through a concrete block? That is no kind of test to prove anything as far as a knife is concerned in my opinion. Anyway... I'm asking these questions retorically to make a point. My point is if the breaking of a blade to read the grain is the be all-end all test then perhaps a sticky at the top of this forum with an explanation of what to look for to determine desirable heat treating and what to do about it if the results aren't desirable, would be helpful. I assume it has been covered as to what to look for and even perhaps what to do about it, but I really don't recall personally, seeing much beyond, "You need to break your blade or else you only have a knife shaped object." It just seems to me it would be helpful to newbs if they had a resource they could look at and see that if "this" happens then make "this" adjustment. Just a thought __________________ Find me on Facebook: https://www.facebook.com/gpopecustomknives/ Gloria In Excelsis Deo!! |
#2
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And to be fair there IS a sticky at the top about testing blades.
__________________ Find me on Facebook: https://www.facebook.com/gpopecustomknives/ Gloria In Excelsis Deo!! |
#3
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I don't think I've seen anyone suggest cutting barbed wire or chopping through a 6" black locust post. The 'standard' usually applied is cutting fresh cardboard in blade length slices (a 6" blade makes a 6" slice so all the edge is used) and count the slices. Slicing hemp rope and comparing the number of slices to what you can get with the best commercial blade of similar design that you might have. And, there's the ever popular chopping or shaving your way through a fresh pine 2x4. These are all good ways to test edge retention, edge geometry, and equally important they are a good test of handle ergonomics which is something nearly always over looked by newbies until they try these tests. Nearly everyone quickly gets the hint when they have a handful of blisters. The fact that you might never do any of these things with your knife misses the 'big picture' . Besides, someone might do similar things with one of your knives some day.
The grain question is harder to address. Yes, there is an easily observable difference in fine grain and grain that is coarse. The grain is about the best indication we can get outside a laboratory that the conversion that takes place at the quench was as thorough and complete as we can make it. If it isn't, there isn't one simple answer as to why it failed. For that, we need a dialog with the person who did the HT to discuss each step and see if we can spot a problem. So, there are pictures on the web of fine grain and coarse grain but by themselves they aren't a lot of help. Before a blade gets broken to look at the grain you can make coupons and break them (little hour glass shaped pieces of blade steel 3" long). Once the grain is good on those then try a blade. Breaking the blade in the correct way will also tell you how tough your blades are by how far they bend before they snap. Sure, if you plan to pry something you'll go get a pry bar...unless you can't. Somebody will pry something with one of your knives someday. It might even be a life or death situation. If that should be the case with one of my knives I darned sure don't want it to fail. And that's a fair piece of the rationale behind breaking blades ... |
#4
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ALOT of this stuff is very tricky,,,,by no means am I anywhere near a expert but I have been around for almost 2 years now and when I first came here looking for advice I got all the advice and things you mentioned, I think as far as the "use and abuse" type of tests its fairly straight forward you want to put that knife through more stress than most users would to see how it holds up, if I can hack through a 2x4 a couple times cut a bunch of cardboard and rope and then the edge is still good to shave hair or paper then I know its going to hold up to someone that wil take it hunting and fishing or any normal use, the grain thing is tricky because your right about it can be subjective what looks like fine grain to you I might consider fairly coarse. this is one reason that not only did I share pics with some of the people that were helping with advice at the time,,,,i physically sent a batch of coupons for some one to break and tell me what THEY though wich deffinitly helped me realise whats fine and whats coarse. most of the time when I break a blade or coupon it hasn't been tempered once you temper it it should break very easily, I know another knifemaker that I met a few weeks ago that lives near me that last year took the ABS journeyman smith test, from what he told me basicly the test goes as follows (as far as the heat treat and performance is concered) its actually very simple first shave arm hair then chop through a 2x4 twice then the blade still has to be able to shave for a second time. finally you strap the first 3 inches of the blade in a vise and bend it to 90 deg IF it doesnt crack in half or have and visable cracks in the steel you pass, I actually think that is a really good way to test a knife because the edge must be hard to go through a 2x4 twice and still shave hair but soft enough to bend 90 deg no problem. as ray said when this is suggested usually there is some communication going on because yeh there is more to it than one or 2 quick posts, when I first came here there was a tread I started that went on and on forever now there was ALOT of info in there but just on HT alone there was 4 or 5 pages maybe more. bottom line yeh these are good test but you have a point from a newbie's eyes its hard to figure out what is what again the grain thing my definition of "fine" might be different than yours.
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#5
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Don't be confused by the ABS test - that is not a test of how your blade should perform. That is simply a test for how that particular blade should perform in the ABS test. For all practical purposes that test actually only works with 5160 or, at least, few of the candidates ever try any other steel for that test because it is so close to impossible with anything else. That test is meant to demonstrate the candidates control over his heat treatment and that is all. It is not how our blades should normally perform ...
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#6
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Preach it Ray!
__________________ Carl Rechsteiner, Bladesmith Georgia Custom Knifemakers Guild, Charter Member Knifemakers Guild, voting member Registered Master Artist - GA Council for the Arts C Rex Custom Knives Blade Show Table 6-H |
#7
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oh no I know that type of HT would not be good for every knife, each knife depending on whats it is going to be used for should be done differently to match the use a exteme example would be a filet knife you would HT that softer so it will flex without breaking, as you said the ABS test is to see if the person that is being tested can HT a knife to a specific role or design. I was just using it as a example of what some test's can tell you about that knife
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#8
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If you want a standard to compare the grain of your knives too get a file and break it. It should have a "silky" gray grain.
Doug __________________ If you're not making mistakes then you're not trying hard enough |
#9
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Exactly Doug, although I call it a grey velvet look, but breaking a small file is a good idea.
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#10
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One addendum to the otherwise excellent idea of breaking a file to use as a fine grain standard: it has to be a solid steel file, not one of the cheaper case hardened files. So, either an expensive file or a very old file preferably with a major name like Nicholson or Grobet. But, any kind of file will do if it meets that criteria be it mill, bastard, rasp or whatever ...
Last edited by Ray Rogers; 12-31-2016 at 08:26 AM. |
#11
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Would recommend making up several coupons of a known blade steel (such as 1084 or W2) and HT at diff temps mark well and break. If done with care you can have a nice reference set. For a long time I kept a set for each kind of steel I used, but they seem to have found alternate residences over the years.
Most don't realize how drastic a diff 100 deg can make.....velvet to cornbread in 15 seconds if you are not paying attention. __________________ Carl Rechsteiner, Bladesmith Georgia Custom Knifemakers Guild, Charter Member Knifemakers Guild, voting member Registered Master Artist - GA Council for the Arts C Rex Custom Knives Blade Show Table 6-H |
#12
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Quote:
as for the ABS knife test, many get caught up in this as the way to test a blade as did I admittingly, so I did many back yard rope cuts, 2x4 tests and 90 degree bends myself and passed with flying colors.......someone please send me my stamp ! all kidding aside there are many options to this for testing durability and edge retention......I'm very picky with my heat treat and am confident that every blade leaves my shop as best as I can make it, no short cuts and no returns... Happy New Year everyone !! __________________ R.Watson B.C. Canada |
#13
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Very true I have done the same with every steel I use many coupons a couple blades to abuse on every new steel and then once in a while. really no matter what test you do there is no end all be all of tests....or I haven't found one anyway if you guys know of one please let me know!! either way its ALOT of trial and error you do the best you can with what you have cant do any more than that Good new years everyone This is one night I am happy I don't live in the city anymore! thousands of people packed in time square to watch a ball with a thousand lights fall....who came up with that?!?!? makes no sense to me never got it and I have lived here my whole life. that is about the last thing in the world I would like to do LOL
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#14
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The "end all" test is using the knife for it's intended design use - over and over and over and over - ad infinitum. If it doesn't do what it's supposed to, then the maker did something wrong.
__________________ Carl Rechsteiner, Bladesmith Georgia Custom Knifemakers Guild, Charter Member Knifemakers Guild, voting member Registered Master Artist - GA Council for the Arts C Rex Custom Knives Blade Show Table 6-H |
#15
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Quote:
My point is, what IS the standard, or A standard? How MANY cuts through cardboard? How MANY cuts through rope? Can the brass rod actually leave the tip of a blade bent if it is sharpened at too shallow of an angle, even though the HT is good? What do I expect when batoning through hardwood? At what point can the edge dull and still be "good"? Or can the edge never become dull? And finally, break the blade and "read" the grain? (Good tip above about comparing it to a broken file. THAT is useful and something a newb can do and relate to) Bottom line. I realize at the end of the day, we each have to determine our own guidlines and criteria of whether our knives "pass" our own testing according to what we expect of them. When newbies are offered advice it seems to me there should be some standard of pass/fail, some "jumping off point" rather than just arbitrary suggestions, and there doesn't seem to be. __________________ Find me on Facebook: https://www.facebook.com/gpopecustomknives/ Gloria In Excelsis Deo!! |
Tags |
advice, bee, blade, blades, block, design, edge, file, fishing knife, hammer, handle, heat, heat treat, heat treating, how to, hunting, knife, knifemaker, knives, make, newbie, post, show, steel, tools |
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