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Hi. Just had this delivered from that online auction site. It was sold as phosphor-bronze. Got it for £20 including delivery. The cylinder measures 2" x 6-3/8" and weighs 2.45kg (5lb,6oz). It is stamped BZ534 and has an interesting pattern of nine dots square at intervals over the surface. The rust seems to be sitting on the suit face and can be scraped off. I was wondering if anyone knows what it is/was? Also, is phosphor bronze best for carving or casting? Thanks.

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Well, it's the wrong color, and bronze doesn't rust so??? :huh:  maybe do the density calculations and look it up to verify it's in the correct weight range for its size to be a copper alloy?  I couldn't find anything about the stamped code in a short search, sorry.

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I did just find phosphor bronze rounds in grade c540 listed as excellent machinability, welding, and brazing, and flats in c510.  So it seems to be in the family...

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WHOOP WHOOP WHOOP!  We have a potential winner: https://alloys.copper.org/alloy/C71700 .  Unfortunately it seems to be the recently discussed beryllium bronze, with cobalt added.  Deadly to play with if you make dust.  I wouldn't mess with it unless you can get it tested.  Maybe a scrapyard near you has a handheld xrf gun?  Or a university, even.  Most archaeology departments have one now.  If you can talk someone into giving it a zap and any sign of Be comes up, run away!

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Thanks Alan. Life-saver (quite literally it seems). I'll see if I can get it tested.

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Got the xrf done today. Results as follows. Cu 80%. Fe 5.5%, Sn 4.5% LAS 10%. The guy didn't know what LAS was but it looks like it might be low alloy steel. How definitive would you take this result?

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Depends on the guy, I guess...  I'd try to find out what LAS means, steel should show as Fe.  

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I would bet that LAS does not stand for low alloy steel, not if it was listed with the other elements.  It makes no sense that it would try to tell you that it is reading several elements (including iron) and at the same time a group of elements (95%+ of which are iron).  Now, it could have been set to LAS->low alloy steel, then tried to run your brass/bronze under that setting, which would not be very accurate.  

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Hmmm. The plot thickens. Thanks guys. Would an xrf gun read Phosphorus and, if so, what kinda percentage should be present? Think I might raise an issue if it isn't phosphor bronze. Might also see if I can find another xrf gun to see if it reads the same. Thank you for the help.

Edited by Charles du Preez

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On 9/5/2017 at 10:54 PM, Charles du Preez said:

Would an xrf gun read Phosphorus and, if so, what kinda percentage should be present?

I wouldn't trust it if it did.  Pretty light element.  The only thing I would really trust those things for is rough alloy analysis, such as is this shiny steel part stainless or not?  I may even trust it to tell me the difference between 304 and 316 (if there is a good Mo reading).  It certainly won't tell you the difference between carbon contents as that is definitely too light of an element.  

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I've just come back from an analysis close to home (as opposed to work). In hindsight I think the original gun said Ni (not Sn), but as I was trying to remember all the bits, I got muddled. They did scan the metal twice and the readings were the same.

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Excuse the reflection.

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Very odd.  When you said Ni I thought Monel, but that's over half nickel, so no.  And you don't normally find iron in phosphor bronze.  Hmmm...

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Yea, quite baffled now. At least there doesn't seem to be any Be in there.

Actually, I just noticed the total is only 99.37%

Edited by Charles du Preez

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I could be wrong here, but the "All Alloy" listing at the top makes me think it is not calibrated to copper base alloys in the current setting, thus things could be a bit off.  And the asterisk next to the Fe (Fe*) would make me question the accuracy of that element specifically.  Here is a specification sheet for C955.  I have made that alloy before and everything in it is relatively safe (i.e. no Be).  Beryllium definitely won't show up on an xrf gun though; way too light.  

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1 hour ago, Jerrod Miller said:

I could be wrong here, but the "All Alloy" listing at the top makes me think it is not calibrated to copper base alloys in the current setting, thus things could be a bit off.  And the asterisk next to the Fe (Fe*) would make me question the accuracy of that element specifically.  Here is a specification sheet for C955.  I have made that alloy before and everything in it is relatively safe (i.e. no Be).  Beryllium definitely won't show up on an xrf gun though; way too light.  

Jerrod,

When things "don't show up", does the XRF gun come up with a total less than 100%, or is it blind to the mass even being there in the first place?  I ask simply out of curiosity as I have no idea how XRF works...

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Also, if you would be so kind, how do we rule out me dying (i.e. presence of beryllium, etc.).

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3 hours ago, Brian Dougherty said:

When things "don't show up", does the XRF gun come up with a total less than 100%, or is it blind to the mass even being there in the first place?

Generally, things will add up to 100% because what you are seeing is a percentage based on what it found.  When it doesn't add up to 100% that means that it found something, but didn't know what it was, or there is some uncertainty based on the reading of one or more elements.  I think that is what is going on with the Fe*.  

2 hours ago, Charles du Preez said:

Also, if you would be so kind, how do we rule out me dying (i.e. presence of beryllium, etc.).

The 2 safest ways:

1) Don't use it (duh, and sad).  

2) Send it out for better analysis.  This will cost a little bit of money.  When I send out my samples from work for 3rd party verification (we have an in-house spectrometer), I pay $65 to get steel chemistries verified by OES (Optical Emission Spectrometry).  If you are lucky, you may be able to find a local manufacturer (e.g. a brass/bronze foundry, avoiding art foundries if possible, because they are less likely to be overly concerned with exact chemistries and thus may not have a spectrometer) and have them run it for you.  If you find one, call and ask for the metallurgist (not sales or anything like that).  Ask if they have a spectrometer and if so would they be willing to run an analysis for you.  If they say yes, ask if they have a favorite beer, or donuts.  I trust you know what to do with that information. B)  Personally, I would start with South London Foundry if I were in your shoes.  

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Thank you Jerrod. I'll give them a shou after the weekend as I am away.

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