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I live in coal country an there is a lot of heavy mining equipment to cut coal, sandstone or whatever else that run into miles underground. Here's my question they're are cutting teeth on the head of the continuous miner called Bits here's what the look like new,

 

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These things have diamond tips and eventually break the base is made from tungsten carbide, can I forge this? is it safe? is it going to give of deadly fumes? I don't know anything about this stuff. the mines throws these things away. I was seeing I could forge these things into useful tools that I could use around the shop. If not they have plenty of 1090 stuff laying around gathering rust I can ask, but they usually reuse that and cut that up and weld it to broken pieces.

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I'm pretty sure the points on those are the tungsten carbide part. The rest of the tooth -- the part they're throwing away when the carbide wears out -- is likely steel.

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That whole page never says diamond on it. They would be pushing that if they were using it. So like the post above it Tungsten Carbide probably mounted in an Abrasion Resistant steel.

Can't forge Tungsten Carbide and AR steel can be useful for tooling but the shape is not a real helpful one to start from. Places buy tungsten carbide scrap. I'd see about selling it and buying known good steel.

However if you do find one with little wear see if it can be used as a drift, IIRC Hoffi uses drifts made from tungsten carbide tank penetraters...

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tungsten carbide and tungsten itself cannot be forged....it breaks apart. The tungsten Hofi uses is from the penetrating tips of anti-tank ammunition and is mostly tungsten, not a carbide. It's not forged to shape, it is ground or sanded to shape. And it is not struck directly by a hammer but attached to a mandrel to absorb the shock. Used in a press it is great stuff for making holes in steel.

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A while back I incorrectly said penetrators are made of tungsten carbide, and someone here (I don't remember who -- maybe rthibeau) corrected me. That got me curious, since WC was the only form of mostly-tungsten material that I was familiar with. In case anyone's interested, I'm pretty sure they're made of one of these alloys, or something similar: http://www.mi-techmetals.com/hd-typical.htm I bet that stuff is spendy!

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Its a no go on those bits, I went to the mines today to look at them, they are so degraded and like y'all said you cant forge them and they are around 2 1/2 to 3 inches round to big for a punch. I'll check out that site Mister Bower suggested but I did pick up some nice bolts they use to hold up the roof of the mines, there about 6 foot long I'm not sure of the hardness, but I did try to cut it with a file and hack saw no nicks or cuts I'm sure that make some handy tools.

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I wouldn't bother trying to buy any of that tungsten alloy. If you could find it, I bet it'd be insanely expensive. (If I had known fifteen years ago what I know now, I would've brought a couple of those penetrators back from the desert out at 29 Palms, instead of the aluminum base of a tank shell.) I just posted it for general information. Those bolts sound interesting, though.

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Carbide is used on just the tip, the main body is a steel alloy. Carbide melts at 5,200 + degrees. The sizes that you listed would be good for hardies, and matching top tools. Scrap carbide is over $10 a pound the last time I checked. Toss them in the forge to shape, and toss the tip into a bucket when it desolders itself.


Don't give up on them so fast. Grab a couple, and see what you can do with them. Free is free, you won't lose anything money wise, but you will gain some knowledge.

To get them down to a more manageable size you can cut them down with a saw..

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That whole page never says diamond on it. They would be pushing that if they were using it. So like the post above it Tungsten Carbide probably mounted in an Abrasion Resistant steel. Can't forge Tungsten Carbide and AR steel can be useful for tooling but the shape is not a real helpful one to start from. Places buy tungsten carbide scrap. I'd see about selling it and buying known good steel. However if you do find one with little wear see if it can be used as a drift, IIRC Hoffi uses drifts made from tungsten carbide tank penetraters...


A gunsmith friend of mine uses .50 cal AP bullets to make punches on his lathe because they're made of tungsten.

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Do I recall correctly that tungsten carbide can be brazed onto the tip of a tool? Perhaps you could cut some small pieces with your grinder and braze them onto the tips of some cutting tools, maybe lathe tools.

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Maybe this will help.

http://www.carbideprocessors.com/pages/brazing-carbide/brazing-tungsten-carbide.html

And check out Weyger's book. He talks about silver soldering tungsten carbide tool tips.

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Many years ago in a previous life we used to silver solder or braze carbide tips onto mild steel shanks to make turning tools,

Both items to be secured together were ground,

We used sheet silver solder or brass, and borax for a flux the wire or sheet was cut to shape and placed between the tip and steel body,

Heat was then applied mainly onto the thicker steel shank initially using a gas/air torch, then as the borax started to mel, the whole tip/shank brought up to final heat, you would see the tip settle and solder/brass ooze out as the tip settled, withdraw heat and allow to cool slowly

Tips may chip in use, but I cant recall them coming apart on the braze line.

For larger tips we sometimes used a close woven brass mesh as the solder medium

The tungsten carbides we used were mostly sintered powders rather than a solid grained mass which negated any forging on them as they would just disintegrate.

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We used Kennametal teeth in our drill bits for years. The tips are sintered tungsten carbides silver brazed or brazed to the shanks. The tungsten carbides are NOT forgable. The shanks are good steel of a VERY durable medium C nature though I don't know a specific alloy. You can contact Kennametal and ask, they were very helpful when I was messin with the things.

The shanks take brazing heat , high orange without degrading so they may be a high alloy though I never tried quenching or tempering them.

Sintering is putting powdered metals of the desired types in a mold and pressing it till it's fused, usually to a medium yellow heat. Sometimes the mix is preheated or induction heated before squoze. (pressed <grin>)

Frosty The Lucky.

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Can you elaborate on that?


At that time it was a commercially availble product, much like the mesh used for spark guards (woven wire) but on a smaller scale.
It was cut to shape/size using snips, and fluxed with a borax mix which was a paste made from water(usually spit for small amounts) which was then spread all over the mesh, this ensured fluxing all the mating surfaces, the brass mesh melting and bonding the parts when heated, you could see it flow when the correct temperature was reached

We also used to have silver solder in various ring sizes, as well as sheet and ribbon It was an engineering toolroom I was working in as part of my apprenticeship in the mid part of the last century

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Yes, it is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery, tools etc..

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Welcome aboard, glad to have you. If you'll put your general location in your header it'll save folk from having to ask.

 

You're talking sintering which is entirely different from forging.

 

Frosty The Lucky.

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