# Gold calculation by micron thickness



## jonn (Jun 11, 2012)

Ok, so I would like to see if there are any math geniuses out there. I'm a bit stumped on this one. Say you have a piece of gold plated copper/ nickel that's 1/8" x 1/8" . About 1/32" thick. There is a 50 micron gold plating all around, ( says so on the label). How many of these pieces once refined would it take to accumulate 1 cubic cm of pure gold?? :roll: I think I may have done the math wrong, but I came up with 1600 pieces. Can anyone help please? :lol: thanks in advance.


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## NobleMetalWorks (Jun 11, 2012)

Here is an online calculator for figuring total Au weight of sheet or wire, it works for plating so long as you know how many micro inches the plating is.

http://www.saltlakemetals.com/SWCalcAu.htm

There are also calculators for Ag, Pd, Pt and Rh

Scott


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## lazersteve (Jun 11, 2012)

John,

Goldsilverpro has posted formulas for calculating the gold on plated items if you know the dimensions and plating thickness. Search his posts with the keywords 'plating calculation' for the information.

Welcome to the forum.

Steve


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## jonn (Jun 11, 2012)

Thank you brown and Steve. I went to salt lake website that you sent a link to Brown and I came up with this: 
Length .125
Width .125
Thickness .001968
Gold weight .0097 grams. There are 2 sides so that should double to be .0194 grams each piece.
Since there are 16 pieces on each unit, that would be .3104 grams per unit.
Could this be right??
The items I refer to are Cat 5 cable ends labeled as 50 micron gold plate thickness.
Each end has 8 tabs on it and 2 ends per cable for a total of 16 tabs about 1/8" x 1/8" that's what I refer to as a unit above. 
So each Cat 5 cable has about .3104 grams? That's about $15.83 a piece?? Somehow I must have miscalculated again.
I did place 8 pieces in a nitric bath and have nice gold foils left in the bottom. I'm just not sure if I did the math right again. If I did, I wonder how much I should be able to sell these for?? : :roll:


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## Anonymous (Jun 11, 2012)

jonn said:


> that would be .3104 grams per unit.
> Could this be right??


Maybe it's me,but that sounds like a huge number for cat5 connectors.Can you post a picture of the label that states "50 micron gold plate thickness"?Can you also give us the manufacturers name?


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## Geo (Jun 11, 2012)

i seriously doubt it would be 50 microns. millspec is measured in micro-inches, there is a big difference in thickness between micron and micro-inches.


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## jonn (Jun 11, 2012)

Belkin, Apc and any rj45 . Do a google search under Cat 5 50 micron gold. I know it sounds like a lot but that's how it's labeled. I have some and the micron symbol is listed with 50 in front of it. Google searches say minimum requirements of 50 micron gold thickness. Did I stumble onto a gold mine?


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## Geo (Jun 11, 2012)

theres a lot of info about these on the internet , and all say 50 microns. but i cant find a spec sheet on them. 50 microns = 1950 micro inches or 1950 millionths of an inch thick.

if it is 50 microns thick, it would indeed be a good find.


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## Anonymous (Jun 11, 2012)

http://www.amazon.com/100-pack-Connector-Solid-Micron-nickle/dp/B000067ONL
100 pack for $19? Something is not right.They would not be selling several grams of gold for $19.
But then there is this website http://www.cat-5-cable-company.com/faq-goldplating-RJ45.htm


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## jonn (Jun 11, 2012)

That website does indeed say 50 micron.


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## lazersteve (Jun 11, 2012)

50 microns = 0.005 centimeters

Specific Gravity of Gold is 19.3 grams per cubic centimeter (cc)

1 inch = 2.54 centimeters 

1 cm x 1 cm x 50 microns = 0.005 cc

19.3g/cc x 0.005 cc = *0.0965 grams of gold per square centimeter @ 50 microns thickness*. 

a) Measure the plated surface area in *centimeters* (1 mm = 0.10 cm) and *multiply the length by the width*.* For cylinders and irregular objects sum the plated surface areas of the entire item*.

b) Divide the *plating thickness in microns by 10,000 *(ie: move the decimal four places to the left; eg: 10 microns = 0.001 cm, 30 microns = 0.003 cm, etc.).

c) Multiply the result of a. times b. above.

d) Multiply the result of c. above by 19.3 g/cc to estimate the weight of the gold plating in grams.


Steve


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## lazersteve (Jun 12, 2012)

For your item:

0.3175 cm x 0.3175 cm x 0.005cm = 0.00050403125 cc

19.3g/cc x 0.00050403125 cc = 0.00972780313 g =~ 0.0097 grams each

100 x 0.0097 g = 0.97 grams per 50 double sided items.

16/50 = 0.32

0.32 x 0.97 = 0.3104 g per cable

At todays spot each gram is : 
$1593.60 / 31.1 = $51.24

$51.24 per gram x 0.3104 grams = Estimated value is $15.90 worth of Au in the cable ends at today spot.

Perhaps all sides of the item are not plated the same thickness? Perhaps only the contacting edges are plated at 50 microns?

Steve


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## Anonymous (Jun 12, 2012)

Thank you Steve.I thought there was a mistake somewhere.


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## jonn (Jun 12, 2012)

Thank you Steve. That's .97 g of gold for 50 items. There are 8 items per end and 2 ends per cable. I think our math is the same or very close. 50/16= 3.125 cords. $51.00 per gram x .97 = $49.47 divided by 3.125 = $15.83 each cable. I suspect you may correct in stating that only the contact end is 50 microns plated. If that is the case then the equation would differ greatly. I will recalculate based upon that assumption without giving any credit to the sides.


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## lazersteve (Jun 12, 2012)

Check this page out:

RJ45 Plating Problems

Note the list as plating thickness in microinches not microns in section 5.1.1 Gold Surface Layer.

50 µ in = 1.27 µm = 0.000127 cm

So our gold drops to :

0.3175 cm x 0.3175 cm x 0.000127 cm = 0.0000128023937 cc

0.0000128023937 cc x 19.3 g/cc = 0.000247086198 g per item side

32 sides x 0.000247086198 = 0.00790675834 grams per cable

Mystery solved. The previously quoted website confused microinches with microns (micrometers). The site linked above also states gold density of 17 g/cc so you are likely dealing with plating that is an alloy. But items number 2 and 3 on the plating section seem to be contradictory?

Steve


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## jonn (Jun 12, 2012)

Just the contact top would equal .0023 per item. X 16 items per cable = .0368g per cable. That works out to be about $1.88 per cable. So a box with 500 cables in it would have $940.00 worth of gold in it. This does not calculate any wall thickness plating at all. Does this look correct to you Steve? That's $188.00 per 100 cables or 200 ends.


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## lazersteve (Jun 12, 2012)

Check out my post above your last one.


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## jonn (Jun 12, 2012)

So, it is micro inches, not microns. Ok so 1 cable would have .00790675 grams of gold. Got it. So 500 cables would have 3.953375 grams of gold. That's $201.62 per box of 500 cables or 1000 ends. Or about .201 cents each. Or $20.16 worth of gold per 100 ends. The reason I ask is that I've come across 74 boxes. Let's do the math together on this one. 74 boxes x 500 cables = 37000 cables. That's 74000 ends at .2016 cents each = $14918.40 or just shy of 10 oz. Troy ? What do you think Steve? Is it correct ?


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## Anonymous (Jun 12, 2012)

Jonn,
the phrase "If it's too good to be true,it probably is" ,applies to recovering gold,as much as it does to everything else.That's not to say that you won't be surprised(in a good way),at the yield of some items,but I highly doubt those items will include Cat5 cable ends.When I said it sounded like a huge number,I didn't say it because I was trying to be mean.I said it because I have been doing this a long time,and I guarantee that no person,or company,ever made it by losing money.You are not going to find $1000 worth of gold,in $50 worth of product off the shelf.There is one guaranteed method to figure out how much gold is there,and that is to process a set amount of the material.


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## jonn (Jun 12, 2012)

Thank you Mic. These items were not purchased off the shelf, and thank you for the apology, but there was no offense taken. I am simply trying to calculate the value of the material that I have come across. I have itemized my math calculations above according to lazersteves figures. I hope they are correct and if so, I may be listing some for sale to anyone who would be interested in refining them. The cables I purchased are attached with a 1' cable that I will be clipping and sending to the scrap yard. The ends have some value and I would simply like to know what to expect from a sale or refining. I suppose I could send them all off to a refiner and pay all their fees and hope that they are honest. Either way, it's always good to do research and I greatly value and respect all the fine folks here at the forum. Hats off to you gentlemen and thank you for all your input.


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## Geo (Jun 12, 2012)

some well meaning people use the the wrong terms for things they think they know (such as using micron when it should be micro-inches). its called misinformation. this forum is trying to end that, at least here on the forum, one person on the internet publishes misinformation and then after it passes through so many sources, its considered fact. here, you will find that misinformation is called out whenever possible to seed the correct information.


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## lazersteve (Jun 12, 2012)

jonn said:


> So, it is micro inches, not microns. Ok so 1 cable would have .00790675 grams of gold. Got it. So 500 cables would have 3.953375 grams of gold. That's $201.62 per box of 500 cables or 1000 ends. Or about .201 cents each. Or $20.16 worth of gold per 100 ends. The reason I ask is that I've come across 74 boxes. Let's do the math together on this one. 74 boxes x 500 cables = 37000 cables. That's 74000 ends at .2016 cents each = $14918.40 or just shy of 10 oz. Troy ? What do you think Steve? Is it correct ?



John,

Let's check your math:

0.007907 grams per cable x 500 cables per box = 3.9535 grams Au per box.

From your quote above you have 74 boxes of 500 cables:

74 x 3.9535g = 292.559g total at 100% recovery

or in ozT:

292.559g /31.1g = 9.41 ozT

at todays spot of $1590.70:

9.41 ozT x $1590.70 = $14957.20

You will not get 100% of spot or free refining plus there is the matter of shipping. Let's not forget that these items are commonly 'faked' for lack of a better word and you may not have what you think you do.

PM me when you get all of the gold plated contacts free of copper wire and plastic. I'll make you an offer on refining a sample to see what you actually have. If the numbers hold true to the math I'll be happy to refine the entire lot. 

Steve


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## Anonymous (Jun 12, 2012)

jonn said:


> Thank you Mic. These items were not purchased off the shelf, and thank you for the apology, but there was no offense taken.


There should not have been any offense taken,because I said nothing offensive.Nor did I apologize for what I said.I stand behind what I said.
I really hope that you have as much gold as you think you do,however I am very skepticle to agree with you,when anyone can buy 100 CAT5 - RJ45 plugs,gold plated 50 "microns" thick,for less than $14 on ebay.You should take Steve up on his offer.He will be fair to you,and honest about the yields.


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## goldsilverpro (Jun 12, 2012)

I sent this email to the manufacturer of these cable plugs. When (if) I get a reply, I will post it.



> On your site, you say the gold thickness on the RJ45 cable plug is 50 microns, which is absurd. Anyone with knowledge about plating would know this has to be in error. The true thickness is likely 50 microinches (1.25 microns), which is considered fairly thick - the gold plating on pins and circuit board fingers is typically only 30 microinches (.75 microns). A micron is 40 times thicker than a microinch and 50 microns would be 2000 microinches. If your plating was 50 microns thick, the gold value would probably be greater than your selling price of the part. I would suggest that you check this out with your plater and make the correction on your site. It is false advertising to say the plating is 50 microns thick when it's only 1/40 of that.



I have spent a lot of time trying to simplify the math of determining the dollar value of gold plating per square inch and have come up with this.

*$/in2 = (thickness expressed in inches) X 10.17 X (gold spot in $/tr.oz.)*

One microinch is the same as one millionth of an inch or, .000001". 50 microinches = .000050". One micron = .000040". 50 microns = .002000"

Therefore, from the formula above:

50 microinch plating = .000050 X 10.17 X 1605 = $0.816/in2

50 micron plating = .002000 X 10.17 X 1605 = $32.65/in2

*Notes:*
(1) The factor 10.17 is the number of troy ounces of gold per cubic inch.
(2) For silver, use 5.5 instead of 10.17 and use the silver spot price.
(3) In the formula, the gold spot price/tr.oz. can be expressed in any currency desired.
(4) If you want to work directly in cm2 and microns, the formula would be:

*$/cm2 = (thickness expressed in microns) X .000063 X gold spot in $ (or whatever currency you want to use)*

For 50 microns (in $), this would be 50 X .000063 X 1605 = $5.06/cm2

For 1.25 microns (50 microinches), it is 1.25 X .000063 X 1605 = $.126/cm2


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## Anonymous (Jun 12, 2012)

goldsilverpro said:


> 50 microinch plating = .000050 X 10.17 X 1605 = $0.816/in.sq.



$0.816/in.sq. / 64=$.01275 per end x 2 ends/wire = $.0255 
$0.0255/wire x 500 wires=$12.75 x 74 cases= $943.50
OR 74000 ends x $0.816 / 64(.125" x .125") = $943.50


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## jonn (Jun 12, 2012)

Thank you Steve, Geo, Gsp, and Mic, you are all very helpful. Mic, if each piece is 1/8" x 1/8" and there are 2 sides and 8 pieces per end then you would not need to divide by 64. The correct formula per end would be divided by 2 or 1/2" per end or 1 full inch per both ends or total cable value. Is this true or did i misunderstand the formula? If true, .816 per cable both ends would be $408.00 per 500 and x 74 would be $30,192.00. Did I do this right??

EDIT: oops, that's 1/2 or .5 per both ends. Or a value of $15,096.00


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## Anonymous (Jun 12, 2012)

I did make a mistake,but I will explain my previous calculation first.The division of 64 comes from the surface area of each connector.You had stated that they were 1/8" x 1/8",which means that there would be 64 pieces per square inch(one side of course).
There is $0.816 per square inch of plating.It takes 64 of your connectors to make 1 square inch.So you would take $0.816 and divide it by 64 which = $0.1275.Multiply that by 2,and that would give you the estimated gold for both sides of 1 connector $0.0255.
You said there are 74 boxes,500 wires in each box,and 2 plugs per wire.
So $0.0255 x 74 x 500 x 2 = $943.50
Here is where I made my mistake.My calculation was for 1 pin per connector.However there are 8 pins in each connector.So we need to take my final estimate,and multiply it by 8 which gives you $7548.That is a lot better than $943.


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## jonn (Jun 13, 2012)

Thank you Mic, you are half way there. You need to multiply by 16 not 8. Which would give you the same number as Steve , just multiply your answer times 2. It will give the same result.


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## Anonymous (Jun 13, 2012)

Maybe I am wrong.I don't think that I am,but it is entirely possible.I will just bow out,and keep an eye on this thread.Good luck John,I really do hope you have the amount that you think.


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## goldsilverpro (Jun 13, 2012)

Other reasons I am totally convinced that the gold is not 50 microns thick. Gold of that thickness is almost impossible to plate with uniformity, using standard baths. Also, it would probably take at least 5 hours in the plating tank. Also, any plating over about 50 microinches would be a total waste of money in that application. 50 micron plating would be in realm of electroforming and would require special equipment and solutions. No company is going to go through all of that just to plate something as mundane as cable ends. Even the highest reliability military plating is much thinner than 50 microns. Look at this link that describes official MIL-G 45204C military gold plating callouts. The thickest on the list is 200 microinches (5 microns) and that thickness is extremely rare.

http://www.artisanplating.com/articles/platingthick.html


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## jonn (Jun 13, 2012)

Thank you GSP. I'm good with the 50 micro inch plating, and I thank you for all your help and information. If it were in microns, it would certainly look different, I agree. I gave some a nitric bath and the foils look similar to finger foils. You said in your thread above that finger foils are 30 micro inch, if memory serves. That makes sense now. Still not a bad find. I will certainly realize a profit and at the end of the day, that's really all that matters. I'm thinking that the best process on these would be to clip all ends, incinerate, ball mill, melt a sample and check copper percentage. Take the rest and add sufficient copper to equal 98% + and send to the electrorefining tank. Any opinions?


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## goldsilverpro (Jun 13, 2012)

jonn said:


> Thank you GSP. I'm good with the 50 micro inch plating, and I thank you for all your help and information. If it were in microns, it would certainly look different, I agree. I gave some a nitric bath and the foils look similar to finger foils. You said in your thread above that finger foils are 30 micro inch, if memory serves. That makes sense now. Still not a bad find. I will certainly realize a profit and at the end of the day, that's really all that matters. I'm thinking that the best process on these would be to clip all ends, incinerate, ball mill, melt a sample and check copper percentage. Take the rest and add sufficient copper to equal 98% + and send to the electrorefining tank. Any opinions?



That's another reason I didn't think of. Nitric acid is mainly able to penetrate to the copper through the porosity in the gold. On average, the porosity is non-existent at about 100 microinches (2.5 microns) for most types of deposits. If you got foils, it can't be 50 microns thick.


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## jonn (Mar 3, 2013)

It seems all the websites have changed their lingo to 50 micro inch now. I will be sending a sample out for assay and keep you all posted. Thanks again folks. Jonn


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## rickdozier (Jun 12, 2014)

I was reading up on this thread and was wondering if the gold content was what was expected.


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