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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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#16
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Whipsaw/Pitsaw & Sawyers
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The kerf (thickness) of the blade steel is flexible on these kind. However a thicker saw blade can be sharpened at a 20 degree angle better for chopping. Here is a chart of junkyard steels and their hardnesss ratings: |
#17
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The problem with those junk yard steel charts is that they're not current. Yes, at one time you might have been able to rely on them to a certain extent but not so much anymore. Junk yard steel is mystery metal and will remain so though some items are safer than other, like auto suspension springs. You still can't say that they are made from a given steel with a given hardness.
It's better to let the scrap steel go to the recycler and start out with a known steel in a known condition with a data sheet for heat treating for making knives. Doug __________________ If you're not making mistakes then you're not trying hard enough |
#18
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Saw Steel Good?
This topic needs a reply from the member who began it. The topic of junk steel repurposed does make a fine new post to begin separately from this one.
The question is asking for help as to the bolo he made and really has been waiting final decision. I think the kerf is too thin on the saw steel used caused the edge to fold when used for chopping. |
#19
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No, the problem is not heat treating the blade. That's been established. The grind has nothing to do with it. You can build a bad Chevelle, but if you don't put a motor in it.... Now, if he had heat treated it properly then you could move to the grind. For any blade to perform it must have 1st the proper heat treat, 2cnd proper grind geometry, 3rd comfortable to hold. In that order.
I hope he goes back and heat treats the blade. If it's a good steel like L-6 it will be as easy to heat treat as any steel he can use. He'll see the performance pop then. Crex, your the first person who ever stated about the file brands exactly what I've experienced. |
#20
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I made a machete with a 22" blade from 3/32" O1 once upon a time. So thin and flexible you could wobble the blade in the air like the blade of a large hand saw. It had about a 20 degree edge on it and a proper HT. You could whack away all day long hitting heavy brush and small trees and never roll that edge.
You can sharpen any piece of steel but not all steel makes a good blade and none of it does without the right heat treatment ... |
#21
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The member that began this post originally may be using the bolo incorrectly. I mean to say in not such technical terms that he might "punch like a girl" when he swings it? THIS MAY BE THE DEFINATE PROBLEM Here is a good sawmill file knife I have a link to: http://pages.ebay.com/link/?nav=item...626648&alt=web |
#22
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1800's saw blades are probably something like 1060, you couldn't pay me to make a working knife from it. It wouldn't do it.
I have made hundreds of saw steel knives ranging from kitchen to machetes. The saw blades ranged from band saw's used to cut steel I beams to large round carbide toothed blades. My personal Bowie was made from the latter. On one test I tried, and failed to destroy it by chopping through a 2x4 3 times. It would still make a clean slice through a piece of hemp rope. I then hammered it point first using a 3lb hammer and pried the grain apart multiple times. After that I put it in my vice and started pulling. I pulled my 65lb vice clean out of its anchors. The knife flexed over about 30deg and went back strait. That's what a properly heat treated saw mill blade is capable of. I just finished a large knife for a guy who does BBQ competitions. I showed this 12" saw mill blade to a young maker. When I picked up a catalog and sliced through it like it wasn't there the young guys eyes got big and said, "I wasn't expecting that". My thought,"yeah, but I do." When it comes to files for knives, testing is paramount. A "saw mill" file can be anything and contain any number of alloys from case hardened to w-2. The maker needs to know what it is. |
#23
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Missing the point that is being stated here - over and over. It does not matter what steel the fella used to make the bolo. If the steel is not thermal cycled correctly for it's intended use, followed by a corresponding edge geometry, he's still going to have a problem.
Even if the blade is made from great quality saw steel (which is in question), if he ground the blade and ground the bevels without paying close attention to overheating the blade, he will still have the same problem. If he has overheated the edge, he has taken the original hardness/temper out of it. Thus causing the same problem. "Kerf", by the way is the width of the cut not the thickness of the blade. It is determined by set of the teeth on the saw. I've run a few sawmills in my day, mostly to put myself through college. I fully agree with Doug on the "Chart". This is based on several years experience using recycled steels - mystery, if you will. While the chart may be somewhat of a guideline for older steel, it's proven over time to be quite inaccurate for most found steels. Only serious testing will determine if the steel is suitable for cutlery - still a subjective issue as I stated earlier and greatly depends on the skills and experience of the testor. That being said, the fella with the bolo, could/should try re-heattreating the blade, if he wants to try to make it work properly (if indeed it can). __________________ 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 |
#24
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Show us, don't just tell us?
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#25
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The take away from this conversation for novice knifemakers should be this:
Any steel used for a knife, regardless of whether it is new foundery steel or recycle saw blades, should be thermally cycled (i.e., heat treated) correctly BY THE MAKER. Only by doing this can he/she varify that the knife is proper for the end user. If you create heat through the grinding process as you shape the blade, you change the performance characterists of that steel. This and other 'unknowns' is why you should not ever rely on the heat treat which was originally applied. Do it yourself. Famed maker David Boye, who cut his teeth using saw blade steel explained in his book (Step by Step Knifemaking: You Can Do It) that all his saw steel was annealed before even starting to grind. Annealing is simple and cheap. Tip: This will also save you money on grinding belts. Then, you create your piece and do the quench and temper as required by the steel type and intended purpose of the knife. I have made many saw blade and file knives. If you are unsure of the exact alloy, no problem. Do the quench (I use peanut oil heated to 120* for any saw steel) then test the edge. I have a rockwell tester but most often, I use a file. If the blade fully resists the cut of the file, I move on to tempering--400* for one hour. If the file digs in, throw it away, don't use that steel again, and share your experience here. Many years of making and rockwell testing such knives tells me that my edge will be between 57 and 59 rockwell pretty reliably. Even file steel (which is normally water hardening W series steels) will test out in this range with this process. Bigger knives will get a second one hour temper after cooling to room temperature. I hope at least some of this helps someone, because if you are not heat treating your knives then you are not making knives--you are making 'knife shaped objects'. __________________ Andy Garrett https://www.facebook.com/GarrettKnives?ref=hl Charter Member - Kansas Custom Knifemaker's Association www.kansasknives.org "Drawing your knife from its sheath and using it in the presence of others should be an event complete with oos, ahhs, and questions." |
#26
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Quote:
https://en.m.wikipedia.org/wiki/Red-short Annealing increases ductility and reduces hardness. It is heated until it glows (recrystalization) maintained then slowly cools to room temperature. Quenched only for copper, brass, and silver. Whipsaw/Pitsaw blade steel from the 1800's is completely wrought mild carbon steel. The advent of this kind of metal during 1860's with iron clad warships. The metal may contain sulphur impurities that will make it melt at uneven temperatures and separate called RED-SHORT. If sulphur impurities are present when heated to 900 F degrees the black/grey steel glows a dull red color as it forms into a iron sulfide/iron mixture becoming crumbly. Pure steel at this temperature instead becomes more malleable. Last edited by Colonel666; 11-11-2015 at 01:12 PM. |
#27
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A quick tutorial on annealing:
Go to your local WalMart and walk to the garden section. Pick up a bag of perlite. It is used for potting plants and only costs a couple of dollars. (Vermiculite also works very well). Then, walk to the tool isle and find a small all-steel tool box. You can typically get one for very few dollars. Just find the cheapest all steel tool box, and that's what you want. Go to your shop, and fill the tool box with the perlite. When you want to anneal something, grab a slab of scrap steel (a bit shorter than the box) and shove it in your forge. When it glows red hot, shove it down deep in the pearlite and shut the box. Now, put your files or sections of saw steel that you want to anneal into the forge, and get them red hot. Pull them out of the forge and shove them down in the perlite with the hot scrap. Make sure they are in the center of the perlite--not against the bottom. Close the lid and wait 24 hours. Done. Your steel is now annealed and ready to be worked and heat treated. __________________ Andy Garrett https://www.facebook.com/GarrettKnives?ref=hl Charter Member - Kansas Custom Knifemaker's Association www.kansasknives.org "Drawing your knife from its sheath and using it in the presence of others should be an event complete with oos, ahhs, and questions." |
#28
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Be glad to. I do have a youtube video of the drop test. That's where it's dropped from eye level point first strait out of temper on a concrete floor. If the point rolls (too soft) it fails, if it breaks (too hard). This is the first test I do out of temper. On my next rough use knife I'll tape the test if you'd like.
You see those guys with ABS Journeyman or Master Smith by there name? Look up the testing requirements for getting that tittle. You think what I put that knife through is tough? As far as the old whip saw, junk steel. With modern stuff everyone has there own alloys, and half the time not even the company you are obtaining them through knows what it is. Any chart nowdays is for a rough guess, what you get may be totally different. |
#29
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Pearlite Microstructure
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The perlite in potting soil is volcanic glass that heated to 1600 F degrees and popped similar looking to popcorn. Vermiculite in potting soil is silicate (sand) like mica. |
#30
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"1800's" - that's 100 years of metallurgy development. During that time major changes and improvements were made in the metal/steel industry here in the US. (Pretty broad statement.)
Andrew is not confusing the issue, just a bad speller. Those with any real experience in knifemaking know that. Cut him some slack. Be careful using wikipedia as a source for technical info - anyone can contribute to wiki whether they know anything or not ....... and apparently many of them are in the "not" category on a multitude of subjects. __________________ 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 |
Tags |
angle, bee, bevel, blade, blades, brass, chopper, drill, edge, file, flat, handle, heat, heat treat, hot, knife, knife blade, knives, made, make, metal, mill, saw blade, spear, steel |
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