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Post by Deleted on Sept 1, 2007 11:37:02 GMT
Have a look at the red hot round bar at about 1:30 into this clip, if you look closely you can see its re-bar. I found these two clips interesting & horrifying at the same time. What are your thoughts.
Heres the second part for those how haven't had enough.
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Post by Deleted on Sept 1, 2007 15:52:43 GMT
why is it so horrifying? They make some pattern welded screw blades out of lengths of combined steel twisted into screws. Bars aren't really that big a deal, it is much easier to get bars of steel than sheets thick enough to turn into swords.
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Post by Deleted on Sept 1, 2007 21:42:26 GMT
The only concern I have is based upon my ignorance regarding rebar. I know it's made from steel, but what kind of steel? What's the carbon content, etc.? If it is fairly good quality steel (not a lot of impurities, etc.) with a good carbon content, then it could possibly make a decent sword blade once shaped and heat treated. Who knows?
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Post by Deleted on Sept 2, 2007 3:39:32 GMT
Re-bar here in Australia is used to reinforce concrete slabs , pillars etc having worked with the stuff i know first hand that even though their are different grades of "re-bar" it really depends upon where the bar originates from as to how close it actually comes to being the grade its supposed to be. I've seen stuff from India & China that is no where near the spec's it's supposed to be to do the job it's required for. Yes people buy it in cheap because it's cheaper than he local manufacturer but it's still required to meet certain standards for good reason, engineering & structural safety. If we cant guarantee the actual quality or content of this product here what chance has anyone got of knowing in a place like that on the Video. How is it realistic to say what they are selling & we will be swinging & or cutting with is safe, how is it even remotely logical to say yes if they cant even tell you what the material mix was to start with. I'm sorry but this scares the hell out of me & i wouldn't knowingly stand anywhere near someone using one of these blades. Would you feel safe firing a gun if you knew no one could honestly tell you what type or mix of metals went into the making of said gun. These guys seem to take great pride & care in producing this product (under the circumstances) & personally i think they would make great wall hangers if the price was low enough but i would not use one, hey thats just me & my personal opinion / choice, everyones free to make up their own minds on the matter.
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Post by Deleted on Sept 2, 2007 4:25:29 GMT
I agree with spud, if they could guantee it was 1050 or higher , than, yes great stuff but without a guarrantee...........yikes. Having said that I have a tanto forged from a gearbox layshaft and another from a Ford control arm, not sure what the steel is but it takes clay tempering just fine and makes a nice blade. Finding good steel in Australia isnt easy,which is frustrating seeing we make it here.
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Post by grahamts on Sept 2, 2007 6:49:45 GMT
Don't know the rights and wrongs of the type of steel, but re the impurities, isn't that the whole point of hot forging, to remove any imputities and leave a more pure steel? As I understand it oil quenching causes carbon migration into the steel thus increasing the hardness, but shouldn't produce a harmon So how come the blade they used for test cutting appeared to have a true harmon when it was oil quenched
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Post by Dan Davis on Sept 2, 2007 12:40:30 GMT
Spud, Rebar is typically .40 carbon, with a variance of up to 10. It is on the low end of the hardenability range but can be hardened into a decent blade. Other than that it is decent quality metal.
Also, a medium to low-carbon steel would be less likely to fail and far more likely to simply deform than a higher-carbon steel; so when working with duffers I would be MORE inclined to hand them this blade as it would be safer for me.
Ronin, Your Ford control arm is most likely 1060 carbon steel and the gearbox shaft could be almost anything.
grahamts, Oil quenching does not cause or allow carbon migration into steel; this is a common piece of misinformation publicized by folks who use oil-quenching techniques to "hype" their products. It is on the order of an urban legend; absolute bull-plaster but everyone believes it anyway.
Oil is used as a quenching medium because it boils at a much higher temperature and thus provides a much more even heat conduction as steel cools. It is also less dense than water so the total heat reduction is slower, causing less stress to build up in the blade. It also results in a slightly softer edge than water for a comparable steel. It is a trade-off where you give up some of the absolute hardness in your blade in exchange for a lower failure rate.
Any quenching medium will produce a hamon if you properly prepare your steel in order to get one in the first place. The brightness and crispness of the hamon depends on how rapidly the steel drops below A1 and undergoes phase-transformation; so a slower cooldown in oil produces a more muted, indistinct and sometimes "muddy" looking hamon. But it will produce a hamon, and the lack of interesting activity is the trade-off for more blades surviving the heat treatment.
Clear as mud, huh? BTW, I once produced a hamon on a tanto by taking it out of the forge and throwing it down in the mud.
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Post by grahamts on Sept 2, 2007 15:52:01 GMT
Thanks wildforge, that was a very clear explanation, don't undersell your communication abilities ;D cheers, Graham
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Post by Deleted on Sept 2, 2007 19:30:37 GMT
if it looks like a sword and cuts like a sword its a sword most swords are made from truck springs so i dont think it make a difference it depends on the steel and the temper look at paul chen swords im sure they use quality steel but they cant get to a set standard with there tempering its always hit or miss unless you rob a bank and buy a albion
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Post by Deleted on Sept 2, 2007 23:26:05 GMT
Here's some data I found on Anvilfire.com
They make the point much clearer than me about you just dont know what material your using to start with.
REBAR: Concrete Reinforcing Bar For some reason every new blacksmith is familiar with or has some rebar. It is terrible material for anything other than what it was designed for. A few smiths have used it to make tools but it should be a material of last resort. A few artists use it for its "industrial" texture. ________________________________________ REBAR varies a great deal. It is one of those products that is sold based on ASTM minimum performance specifications which do not specify the exact material. OLD rebar is pretty trashy stuff being rolled from the cut off ends of billets that often had pipes, inclusions and cold shuts. NEW modern rebar is a much better product but still meets a performance spec not a material spec..
REBAR typically comes in three grades. Structural, Intermediate and Hard grade. Hard grade was often made from re-rolled railroad rail (50 - 75 point carbon) or scrap from making same. Structural grade is roughly the same as A36 structural steel. Intermediate is most common. Chemically phosphorus is limited to 0.11%.
The problem with using scrap rebar in blacksmithing as in using any other scrap is determining exactly what you are working with. The textures rolled onto rebar vary from manufacturer to manufacturer and can be an identifier or even make it collectable like old barbed wire. RE-BAR Structural Intermediate Hard Tensile 55-75 Kips 70-90 Kips 80 Kips min Yield (min) 33 Kips 40 Kips 50 Kips Concrete Engineering Handbook, LaLonde and Janes -- guru Sunday, 12/27/98 21:36:21 GMT ________________________________________ Is rebar good for tool making ? Can it be hardened ? Mark - Tuesday, 01/16/01 19:29:13 GMT Rebar: Mark, There are three different grades of rebar with different hardenabilities. Then there is OLD rebar which is generally non-specific as to specs or quality. No version is designed to be used as a tool steel. It IS done but I don't recommend it. You are much better off to use spring steel or recyle old tools. - guru Tuesday, 01/16/01 19:44:42 GMT Rebar: Concrete reinforcing rod (rebar) is specified in three grades by minimum strength. This means there is not a specific material spec. So it can be plain carbon OR alloy steel. Since the specs are minimums the strongest can be used to replace the lower two grades. Steel much stronger than needed can also be used. I believe the high strength grade can be satisfied by a medium carbon steel (30 to 40 point carbon). Long ago rebar was made from "scrap". This was cut off ends of billets that has a core shrink and produces bar with a cold shut. It also varied in carbon content from one place in the bar to another. Pretty nasty stuff but it met the specs of the time. It is not unusual to come across this material today. Sound like a vague answer? Its a vague material. Every piece you use may different from the next. I prefer not to use it except for what is was designed for. Old spring steel is too easy to come by and is a much better material. Using scrap like springs you still don't know exactly what you have but you know it was a better quality material to start with. You also have some clue to what it might be. - guru - Friday, 01/19/01 04:52:22 GMT
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Post by Deleted on Sept 3, 2007 0:11:57 GMT
Rebar is crap steel, you don't need super high quality to reinforce concrete. I would not use it for a sword, the carbon content varies far too much and is too low from the start. YOu have to realize that, when you forget a blade, you are going to loose a lot of carbon, so you have to start with a very high carbon content, well over 1 percent, even 1.5 if you want to end up with a blade that has .6 or .7 percent carbon. This steel has that to begin with, so what you would end up with in the end would be a sword far too soft, and with carbon content way too uneven to be of much worth as a sword. You'd have to fold the hell out of it for one thing to get the carbon content even, and that is labor intensive, why do that with crap steel when there is much much better quality out there?
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Post by Deleted on Sept 3, 2007 1:38:27 GMT
If anyone is wondering, 1 Kip = 1000 lbs.
Tensile Strength is point of absolute failure.
Yield Strength is point between elastic deformation (flexing) and plastic deformation (bending), causing permanent deformation.
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Post by Deleted on Sept 3, 2007 2:47:19 GMT
If your trying to say that rebar is actually great stuff by presenting us with strcutural stress number that rebar must withstand, dont bother, its being used for a building, not for a sword, completely different criteria apply. Insofar as use for a sword it is not good, but is is still steel, so of course it can withstand a fair amount of stess, so can the concrete. Remember it is just there for reinforcement, it is not actually handling most of the stress. Thats moot anyhow, were taking about swords. For a sword to be good it must A, have a high enough carbon content to harden well but not be too brittle. B, have an even carbon content throughout, so you don't gett spotty hardening, with some areas harder then others. Rebar meets neither of these requirements. I won't even get into the strengths of alloy steels verse non alloy. Sufficient to say, while sure you could make a sword out of it, I could make a sword out of the bumber on my car too, the question is, why would you?
Truth be told anyone using rebar to make sword on a regular basis is doing so because it can be had for cheap, or even for free if you know where to look. It would be getting used by a cheapskate sword maker. I can understand someone using it to develop skill, work it without having to worry about a large loss of money if one bought an expensive bar of alloy or other steel. To use it for regular sword making though, is not so responsible I think, for that purpose it is just not homogenous enough in its carbon content, or high enough in it to produce a good quality properly hard blade. For experimentation and fun, good, for making commericial or custom swords, bad.
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Post by Deleted on Sept 3, 2007 7:07:35 GMT
Quote titan"sword most swords are made from truck springs" Where did you hear that? Even in China they forge from flat bar stock, you can even get flat folded bar stock I beleive. Quote Wild Wolf"Ronin, Your Ford control arm is most likely 1060 carbon steel and the gearbox shaft could be almost anything." I thought the control arm might be around the 1050, 1060 mark the smith that made them scounges steel from where ever he can that might be decent ,of course it limits him in the size of blade he can make.We tried useing motorcycle chain but he couldnt get his forge hot enuff to weld it, and it was full of gunk that was impossible to get out even after weeks of degreasing.
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Post by Deleted on Sept 3, 2007 12:18:40 GMT
Guys I’m beginning to regret starting this thread as some are taking this in a rather overly personal direction, passion is a wonderful thing but being a member of a forum means not only sharing you personal thoughts, feelings & experiences but also the ability to consider the same from others. We all are entitled to our opinions & to put forward what we consider logical conclusions from our own knowledge base that does not mean we have to right to make anyone seem less for becoming part of the sharing experience. Let’s play nicely with others, before our toys get taken away.
Boy didn’t know I had a diplomatic side normally people wince as they read my memo’s or at least ask for the next to written on asbestos to lessen the burning sensation LOL.
After all I am a SNAP (sensitive new aged puppy).
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Post by Deleted on Sept 3, 2007 12:45:14 GMT
I'd say your maybe a little too sensitive and are reading a bit much into things. I'm looking at everyones posts, and no body from what I can see took anything personal, except for you, lighten up man.
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Post by Deleted on Sept 3, 2007 13:32:41 GMT
maybe I am ,
Thats just me, But i didn't say people were taking this personally but rather in a personal direction i know its a fine line but having started this thread i cant but help feeling a little responsible for the overtones.
any who for whom the bell tolls man.
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Post by jw on Sept 20, 2007 23:37:11 GMT
Rebar couldn't be any less strong than raw tamahangane its all in how you forge it, isn't that THE point we have learned from the Japanese?!?!!?!?!?!?!?!?!?!?!? Carbon lost, add rice straw, too much carbon, pound it out... Typically all construction steel in A36 meaning it is at least 36,000 psi. Re bar can be made as high as 70,000 psi which is for high tensile strength applications (high rises). IF you can homogonize with accuracy how much carbon you have you can determine the finished strength of the steel but you would have to be a really, really good smith with lots of time to test and experiment.... Not my first choice, but neither was black sand... ;D God, i'm glad Kensei is gone!!!
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Post by Deleted on Sept 28, 2007 13:37:58 GMT
What's so surprising/? Hero edge swords? and you don;t expect them to be $hit?
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