#21
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I have copies of all b&a literature I can copy and send if you want its basic instructions on die setup and lube and such. george
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#22
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If you manage to get any of the B&A swaging die info into electronic format I'd appreciate anything you're able to share.
I'll read just about anything I get my hands onto at the moment. Looking for info on draw & trim die design at the moment also. Trying to get a 1.25"-1.35" 257 cal jacket. Need to pick the right J4 jacket to start with to ensure correct length + ? to ensure the pinch trim works 100%. |
#23
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I guess I can try to scan and send also have rorshach original directions.the draw dies are fairly simple and straight forward.the pinch trim die is alittle more complex not saying they can't be made, they can with standard machine equipment. theres just quite of few parts to make. george
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#24
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Quote:
From experience, basic EN's can be hardened to +60 HRC with heat treatment. I'll ask the queston of my local EN plating expert, to see what he thinks of coating tool steels and tolerances. |
#25
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aaron, I have worked with e.n. when I worked on the outside it did help with wear resistance, but also seemed draggy for no better word at the moment. also have tried ptfe coatings these were very slick, but at the time same as chrome were very limited on depth vs. dia. I still feel ferro-tic might be a better choice over steel and not as costly as full carbide. I have a couple of pieces here just need time to mess around. george
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#26
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I caught up with my local EN expert. He said the EN+PTFE solutions were almost impossible to apply correctly. I mentioned the EN+Boron Nitride solution and he commented that solution aggitation, BN grade and BN concentration were important. He gave me some 20-30 nm BN to try.
The NRL seem to be making some good progress with interstitial hardening (IH) of stainless steels with carbides. Producing a 20-30 um layer on 316L with a HV of 1100 (off the HRC scale). I saw a presentation by Paul Natishan in November last year that showed even under severe deformation, the hardened layer did not thin out or crack. They are focused on corrosion protection, but I can see IH possibly being applied to tool steels. |
#27
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20-30- microinches sounds like perfect amount and hardness sounds excellent how is finish when done tinitride is harder but actually has a higher coeffiecent than uncoated. I have some boron nitride powder around somewhere. it was being tried in barrels to cut fouling didn't seem to go far though. george
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#28
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Here is a public link to the hardending of stainless http://www.swagelok.com.au/downloads...%20article.pdf
Might be a useful process for die material. Probably more useful for 416R barrel wear and corrossion actually? |
#29
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I've been reading the mail here for some time, and it has been very interesting. I don't make bullets, but have worked (metallurgist) in most of the industries you have been discussing, including carbides, tool steels, titanium, PM parts and specialty wear resistant coatings.
Personally, I would be concerned about using a very thin coating (IH) of any reasonably loaded 316 SS. I will read the Swagelok article tomorrow. You need to have the proper substrate hardness to support the coating. Think of it this way, if you step on a piece glass on a hard floor, you can probably step on it safely without breaking it. If you step on a piece of glass on top of a pillow, or some rags, you will probably break it. The design of good conversion coatings like the nitrides and carbonitrides have to be supported by the substrate alloy, same as TiN and TiC coatings done by PVD , CVD or cathodic arc. If you ever do go solid carbide dies, try to be careful of the cobalt content, whch can run from 2% to 20%, and that greatly affects the hardness and toughness of the carbide. The carbide grains size is another big factor, and for the fine finishes, strength and hardness, using a "sub-micron" tungsten carbide grain might a good choice. Hope this might help some. |
#30
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that's a good point I didn't even consider, but being I only make carbide its really not an issue to me, and you are right on with colbalt content I prefer 8% micrograin its pretty easy to work wears well and doesn't seem to have flaking issues that the lower % colbalt have.still would like to see if I could use ferro-tic for a less expensive alternative.thanks for the input george
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