Magnet Test on a Real and Fake Engelhard 100oz Silver Bar
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- čas přidán 23. 11. 2010
- [Be sure to see our video on using Ultrasonic Thickness Gauges to accurately determine if a bar is made of real silver]
This video shows you how to use the "magnet test" to help determine which 100oz Engelhard silver bar bar is real, and which is fake (made from lead).
Silver is diamagnetic, meaning that a magnet will not stick to it, but you will feel strong resistance when moving a strong magnet on the surface of the silver. Although lead is also diamagnetic, it is much less so, as this video shows.
Note that this test will likely not detect real silver bars that were hollowed and filled with lead (the ring test might, however).
The magnet test can positively determine that a bar is fake, but cannot positively determine that a bar is real. For a very accurate test, you can use an ultrasonic thickness gauge (check our our other videos to see one in action; we were the first to use this technique).
See About.Ag for more information. - Věda a technologie
Although posted 11 years ago, this information is relevant today. Thanks for the video!
For coins and small 1oz -2oz bars I built the rig using two hard-drive mags and it works great. You don’t have to worry about the angle of the piece you’re testing. When you use two mags bolted together with a little slot between then you can pass the coin/bar through and feel the pull of the piece even if you hold it straight up and down or any angle.
I’ve only seen one or two vids on how to make this type rig and they work so much better. I’m thinking about making a vid showing what I’m talking about.
So many people just don’t understand the concept of mag testing silver. They think if it doesn’t STICK then all is good. That’s just not the case.
If anyone is wondering..he got that rare earth magnet from an old 3.5" desktop harddrive. Each HD comes with two of these. Took me about 15 minutes & a couple of stripped screwdriver bits to remove them. It would also help to do the ping & weight test along with this magnet test. Excellent video
The ice test would work great here. Silver has the highest thermal conductivity of any metal, and lead has lousy thermal conductivity. So you should see a huge difference in ice melt speed between the two bars.
Thanks!! as of today......... You have 28 Haters which makes me believe...... They are 28 Fake silver sellers.
Up to 63 now.. lol
91 fakers to date
107
115 fake silver peddlers
Or maybe some people just think the video should have been 30 seconds long instead of 10 minutes
@remsensor The problem, though, is that while lead is about 8% heavier than silver (lead is 11340kg/m vs silver's 10490kg/m), lead can be alloyed with another lighter metal, such as tin, to get the density exact. An 80% lead/20% tin alloy is simple to produce (4:1 ratio), and weighs 10,528kg/m, or 0.3% more than silver. It is believed such an alloy was used in the lead-filled Engelhard bars (see About.Ag/Lead100OunceBars.htm), which even Engelhard had troubles distinguishing.
There are devices that measure the speed of sound in the material.
Where did you get the bar from? After I saw this video I had to go and check all my bars!
This is one of several bars that were sold to people for a bit less than the spot price (about 10%-20% less). One of the people was kind enough to let us borrow one for testing.
So awesome feeling the force in action.
I just tried it for the first time with a kilo bar.
Sure enough when the neodymium magnet gets within an inch of the bar, you feel a resistance. It's not nearly as strong as trying to stick the negative sides of two separate magnets together. It's like 1/100 of that, bit still enough to really feel.
One thing to get straight is that "pulling" 2 magnets apart requires a LOT more force than "sliding" them apart. You can slide (ie: separate) two n40 magnets with just one hand, if they are the same size as is apparently used in this video.
In conclusion, if you can separate two magnets by pulling, not sliding, them with one hand, then they are probably not strong/big enough for this test.
Excellent demonstration. Thanks for sharing the information.
Copper is diamagnetic (lead is, too), but neither exhibit the behavior nearly as much as silver. Copper is less diamagnetic than lead. Copper is less dense than silver, so weighing an coin/bar and comparing the dimensions to a real one would easily discover a copper-based fake (unlike lead, which can weigh the same as silver when alloyed with other metals).
Best tutorial on CZcams 👍👍👍
Thanks AboutAg, appreciate the heads up :)
diamagnetic means it repells magnets. you are talking about eddy currents. because silver is verry verry conductive it will attract a magnet when you move a magnet across it's surface. because it's generating an electric current and basicly turning the silver into an electromagnet
Yes and yes. Moving the magnet causes an eddy current, which causes the diamagneticism. The level of diamagneticism varies in different metals, with silver more diamagnetic than lead or copper (two common materials used in fakes). The magnet test (as used here) is not very reliable (simply because the results are subjective). If an object purporting to be silver is attracted to a magnet, however, that does prove that it is not silver.
Good comparison. I didnt realize it would be slow on lead. I subbed. thanks
How's it going AboutAg!
As far as testing coins(such as Silver Eagle/rounds) with rare earth magnets, would you consider this test pretty foolproof? Or is it possible that there can be a thick enough silver plating on a fake coin or round so as to appear that it passes this test?
Thanks! Scott
For this bar, a ring test would work well. For a fake made out of other metals, however, it might not work so well (I cannot tell the difference between silver and copper). One catch though is that real silver sometimes will make a 'thud' sound.
You should cut about a half in off the height of that bar so we can see the internal composition.
Hey, a question for ya. How did you get the magnet off the metal bracket that holds the magnet to the hard drive? It's glue one right?
Or you can just smell, and taste lead. (Don't recommend licking lead) Silver, and Gold do not have a distinguishable smell, or taste. Copper has a strong scent, and taste, steel does not have very strong smell, but for me, it has a strong taste. This will more then likely not work if the product in question is plated in the real stuff. Hopefully this post is helpful.
@beaverbox The best test for gold plated (or layered) tungsten bars is an ultrasonic thickness gauge. Using a magnet test might or might not work well as a test, depending on how much gold (or silver) was over the tungsten (the magnet test would work best if you had a sample of a specific fake bar, and wanted to test others to see if they were the same as the fake one).
Good to know!! Thanks for the info!!
I have an engelhard 100oz poured and I’m wondering if it is normal for the sides to have grinding scuffs as well as parts of the bar showing a copper tint to it…copper tint mostly appears in the small pores
Interesting video , thanks for creating this.
Do other metals have diametric qualities less than silver but greater than lead ? Always wondered why Bullion counterfeiters didn't alloy some small amount of steel into their bars to simulate silvers diametric quality.
Don't know if someone's already posted about this: Silver isn't especially diamagnetic. The property that causes the magnet to slide slowly is that silver is the MOST ELECTRICALLY CONDUCTIVE element. And a magnet moving past a conductor causes EDDY CURRENTS which resist the movement. If that bar were filled with copper, the magnet would behave the same.
What is the reason that fake silver doesn’t attract magnets, or the other way around? What material is the fake silver made out of to not have a magnet stick to it?
would it be possible to get a mix of copper and lead to both simulate silver's mass and silver's eddy current effect which you are seeing with the neodymium magnet? I can wave a 5lb ferrite bar magnet at a bar of copper and feel strong interaction.
The person who submitted it got it from an auction site, from a seller in China.
A number of different metals attract a magnet, not just iron.
Silver is called "diamagnetic", which acts differently. As you move silver near a magnetic field, an eddy current. So moving the strong magnet near the silver will generate resistance that you can feel. When still, the silver and magnet can be close and will not move towards each other.
In most cases, rounds and bars are treated the same when you sell them. 1 ounce silver bars often have a slightly higher premium (when buying or selling).
Thank you so much
I am planning on purchasing Maple Bullion gold coins and was advised to use a neodymium magnet in conjunction with an electronic gold tester (non-destructive testing).
After watching this video, I come to wonder how this method would accurately determine what's really underneath the surface. Suppose we have a plated gold coin, and the experiment used here basically tests of how well/fast the magnet slides down the coin at an angle. Question: couldn't they come up with the right mix to fake it.
where do you work to buy all that
Couple of things. The phenomenon being observed in this video is not diamagnetism it is simply Eddy currents from the magnet moving past a conductor, in this case the silver bar. You would observe the same phenomenon if you slide a magnet over a copper bar. This is a common high school or college physics demo, though they normally drop the magnet inside a copper tube or use a ring magnet over a copper rod so the effect is even more pronounced.
The only property of the metal effecting this test is the electrical conductivity of the outer layer of the silver bar, though the silver or other conductive material must be thick enough to have a low electrical resistance. One could silver plate a solid copper or copper wrapped lead alloy bar and get the proper density and have the magnet move slowly over the bar. To see what is inside the bar you need to do a test that tests properties unique to silver, and deep inside the bar. So a thermal conductivity test from one side to the other, not a simple surface conductivity test. A speed of sound test, though I am not sure there is a simple way to do this, could work. An x-ray picture would certainly show if the bar was drilled and filled, maybe if it was clad (if the cladding is thick enough).
Density tests will work if the faker was careless and used a lead alloy with a different density than silver but, because silver is relatively low density, it is easy and cheap to match the density of silver with a lead alloy. Density testing is really only conclusive if it show the wrong density, not if the density is correct. The only precious metals that can give a virtually conclusive density test is a pure platinum bar or coin because only a couple of extremely rare and expensive metals, osmium and rhodium, have densities as high or higher than platinum. Tungsten is a relatively cheap metal that can be alloyed to match gold exactly but it is not dense enough to match platinum.
The problem is that different forms of silver (and copper) make different sounds. For example, a 10oz bar will make a different sound than a 100oz bar (and 2 different 10oz bars of the same variety can even make different sounds).
Would the Hollowed out bars that are filled with lead still weigh the troy ounces stamped on them?
Johnny Tran if someone just wanted to weigh it to see if it was fake, which wouldn't work, a troy ounce is a troy ounce. a pound of lead weighs the same as a pound of feathers.
You need a good big scale to do an SG test with the big bars, but the 1 ounce rounds/bars are very easy to check by doing a specific gravity test.....good scale, glass, water, something to hold the round or bar. Can anyone say if this is done by silver buyers? I used to have a bunch of silver when I was a kid.....paid around $3 an ounce....saved up my paper route money and lawn cutting money, snow shoveling etc.....and wound up with (2) 100oz Engelhard bars, several (10) 10oz, (10) 5oz, and (8) 1 ounce rounds....I had bought 10, 10 and 10, but gave 2 away as gifts. This was before the Hunt brothers tried to corner the market, and I had forgotten about all of this. I had ordered from a coin magazine....a good sized bullion dealer. I felt like a wealthy miser stacking and looking at the silver!!! lol....still would rather have it, but can't afford it!! I forget how old I was, but I remember hearing about the prices soaring, and I held out at 40, 45, and sold everything at $48 an ounce!! My father was shocked when I showed him the check and said "This was my paper route money!!" I bought a brand new car and paid the first years insurance and had plenty left over!!! People asked how much the beautiful car cost, and I would tell them $700. lol If I had the money, I would have a walk in vault filled with gold and silver bullion...why? No idea...just love the look and feel.....Fort Knox? lol....Now I love American colonial coins, but the main problem with precious metals is they don't pay dividends, so fine for a hedge, but not great as a main investment at all. I just got very lucky as a kid!!!
....and thinking back on subsequent investments, this was the LAST time I did well!!!!! LOL
You sold all that silver, and bought a car?
I believe diamagnetism is really not the reason. Instead this is due to the Lorentz effect caused by the eddy-currents induced in the metal by the movement of the magnet. These currents create a magnetic field which opposes the movement of the magnet that causes them. Since silver has a much higher electrical conductivity than lead, this means the induced currents are higher, and consequently the field resulting from them is also higher (thus the magnet moves more slowly). Provided the silver coating on the lead is not very thick, this should always work. You only get into trouble if the bar has a layer of copper underneath the silver, because copper has a very similar conductivity.
In fact, this makes use of the same effect as eddy current conductivity meters which use the magnitude of the magnetic field produced by the currents induced in a metal by an oscillating magnetic field to measure conductivity. Unfortunately, these things are rather expensive, so this seems like an excellent alternative. Thanks for sharing!
Yes silver *slightly* diamagnetic, but that's not what explains what's going on here. Silver is less than 3 Xv. Pyrolytic Graphic on the other hand, is over 40 Xv. The effect you are observing is called "magnetic braking", caused by "eddy curents" (see wikipedia for both) forming in the material as a magnet moves past them. (lots of cool videos here of people dropping rare earths through copper pipes) I've been looking for a table on succeptability to eddy currents and can't find one, but it appears to be proportional to a (non-ferrous) metal's conductivity, making silver and copper among the best, and close in value. If you tried this test on a large slab of PG (not that you could find one!) you would find that the PG *repels* the magnet, and does *not* brake it. You can levitate little chips of PG on a grid of magnets. I have a few here, the effect is quite small but enough to levitate them 1-2mm. If you tried to slide a rare earth on a PG plate, it would beat all other slide tests because the magnet wouldn't even rub as it fell down. Unfortunately, all this means is that a copper slab with a silver plating on it would pass your slide test with flying colors. I do thank you for testing lead though. I was trying to figure out if lead braked well, and you clearly demonstrate it does not. Let us (me) know if you find a chart showing the braking capacity for various metals. It's a useful way to expose a fake, although not useful at vetting a genuine.
Silver plated trays also slow the magnet down dramatically and can fool a person just relying on this, so as you said in your description, you can tell fake silver for sure, but no guarantee it is only sterling.
so is the only way to test for lead filling to cut in half?
Is a silver round the same as a bar when you go to sell it?
How much does the fake weigh and what are its dimensions compared to the published dimensions?
very awesome indeed. I didn't realize there are so many easy ways to authenticate precious metals!!
I was shocked to find vintage Engelhard bars shaved on some edges with a really rough file. Looks like yours is too. Thanks for posting.
Shows they've been assayed
In all fairness, you came here to watch a magnet test video -- what did you expect? :) As stated, using an ultrasonic thickness gauge (we were the first to do so for testing silver bars) is a nearly perfect test. But, if you don't have a spare $200 for one, and have a $2 magnet, you *can* detect many fake silver bars this way. I think a lot of people hype this video as being more than it is; if someone else made a claim, I cannot be responsible for that.
This one, oddly enough, weighed less than a real silver bar. However, if they had put some effort into it, they could have made a bar the same shape/size as a real 100oz Engelhard bar, and had it weigh exactly the same. In fact, the old 'drilled-and-filled' Engelhard bars from the 1980s had the same weight as real Engelhard bars.
@MRsmileyz1 I'm not sure what fact you are referring to -- you do need a strong magnet. A neodymium magnet is strong. A typical refrigerator magnet is not.
so what do u suggest for 1oz rounds? smaller magnet?
could you make a ramp out of a magnet, so that you could let coins slide down it to see if they are silver?
I was thinking the same thing too Bob. A bent thin plexiglass ramp with a lip at the end to hold multiple bars. Now they are all at the same angle and you simply place the R.E. magnet on each bar and compare the slide results.. Seems like a decent way to gain some valuable info about the bars in question but I also agree that further testing is in order.. Destructive testing as a very last resort.
So if you are correct this is a point in favour of gold where this cannot be done ?
Thanks for the great information. I'm just now getting into silver for my kids. If you are unable to do that test, the bar is in another state, it's in an auction and it says that it's 99.99% silver, does that mean the bar is silver, at least that is what they are saying, am I right? Thanks for your time
Good video, thank you you the information.
I am starting to collect silver so I will be picking up a magnet and acid (for the acid test).
where did you get the fake bar at?
I thought silver repels magnets so why would the magnet slide slower if its pushing away the magnet?
how did you get that fake bar? did you buy it????
Lol was that a Hard drive magnet? I love how strong they are!
This is a GREAT method for testing flat silver. Even coins...if you have small neodynium magnets, which I do ;) Works like a charm. Thanks a lot.
Where'd u buy them
Just by looking I guessed the top bar
how dose it work ontungsten plated gold n silver bars ??
Weighing is a good step, but the FBI examined lead-filled silver bars and stateed "weighing the bars provided no indication of adulteration". So weighing alone isn't quite enough to prove a bar is real.
Real silver is often over (or occasionally under) by up to ~2-5% depending on the manufacturer, size, etc. That gives counterfeiters plenty of room for error.
My favorite test is using an ultrasonic thickness gauge.
@georgemargaris That's because pure silver and pure copper have very similar conductivity. Silver is slightly higher. So they both produce similar eddy currents when you move a strong magnet over them. That's why the magnets slides down both at about the same speed.
We haven't done a magnet test on gold, and the effect might not be as noticable on a 1 ounce coin/bar.
That said, it is very hard to come up with an allow that comes close to the density of gold (where the weight and size would be the same as a real coin/bar). Tungsten is about the only feasible option, but it has different magnetic characteristics than gold/silver.
@machinationu No, mixing copper or aluminum with lead would greatly reduce the conductivity. The magnet would slide down MUCH faster.
I need to get a magnet!
Find on internet iodium magnet
Or u can find it from your old harddisk
How will the magnet react with a Nickel bar plated with silver?
@georgemargaris That is very useful information; I confirmed this testing with a copper bar here. Copper, too, is diamagnetic, and a strong magnet will move down a copper bar slowly.
That is to say, finding the right mix as the content to exhibit similar degrees of attraction with rare magnet like the one used.
How did you get the fake bar please explain story, thank you.
Where did you get the fake bar?
@HaloHamstur Lead and silver have almost the same density. Lead is slightly denser than silver, but it can be alloyed with another lighter metal so that the density is identical to silver. Therefore, two metal objects of the same shape and size could weigh the same, even if one was real silver and one was not.
@RaMpAgExMoDz Where are you getting your silver prices? It's actually more like $3100 - $3300 for a 100 oz. bar.
Not diamagnetism, it's because of hans Christian orested discovery. He discovered that a moving charge, such as the current in a wire produces a magnetic field perpendicular to the direction of it's motion. It's all about field theory, electricity and magnetism physics. Hand rules will also explain why this happens. Learned this is physics :)
does anyone know where to buy from a trusted gold silver supplyer
Thank you
@Nomoreidsleft Although this bar was noticably light, you can make a lead alloy that has the same density as silver. The best test, though, is the ultrasonic thickness gauge (see the other AboutAg videos), which is one of the few tests that can accurately detect a fake silver bar made of lead.
How did you get stuck with a 100 ounce Lead ingot?
Thank you for your replies. Please allow me to ask one last question, if you were to purchase 12-16 one ounce 99.99 bullion gold coins (regardless of who the seller is -- b/c you simply can't trust anyone) where you need accuracy, which testing method would you use?
What are some legitamite sites to buy silver.
I tried it on a quarter and it slides down slowly why?
It might be possible to do so. The problem is that the counterfeiters have many things to balance -- getting the mass as close to silver as possible (to prevent the bar/coin from being too thick or too wide), plating, passing the 'ring test' if possible, not being attracted to a magnet, etc.
My guess is that an alloy of copper and lead (apparently called molybdochalkos) would be difficult to work with, but I am not an alchemist!
@AtomicEmporium i thought this originally as well and mentioned such in my videos, but gold, which is also a great conductor, doesn't display this effect. I does have to do with diamagnetism. I suspect the repulsion is enough to slow the moving magnet but not kick it off given the mass of the magnet.
The way coin dealers were doing it was to drill a small hole. But, people then want a discount on the bar. The best non-destructive way seems to be using an ultrasonic thickness gauge (but, they cost $100-$200 or so). We've got another video that shows how to use the UTG.
Hi, great series. Could you do a similar set of tests to show how to spot fake silver rounds? Specifically, Canadian Maple Leafs, American Eagles, and Austrian Philharmonics? There are a lot of fake Eagles floating around, and I'd suspect most new small buyers would gravitate to the coins rather than the 100oz bars. You'd be doing them a great service. Thanks!
@mtube620 It is because of an eddy current that is generated when the magnet is moving. The faster the magnet moves, the stronger the current (causing the magnet to move slower down the bar).
Woah fakes in that size too! Thanks the video. I need to be very vigilant when not buying from the dealers.
Could you imagine paying out for it. Then finding out?
will it work with magnetite?
@vorkev1 I apologize if I was not clear. The magnets I am referring to are extremely difficult (or impossible) to pull apart with just one hand. If you can pull apart two magnets with a single hand (I.E. using your fingers), then either they are not strong enough to use to test silver with, or you are a lot stronger than I am. :)
That is correct. It is possible to use tungsten (which has a higher mass than gold) in gold bars, but it is quite difficult to do. It would likely be nearly impossible with 1 ounce gold bars/coins.
i have 1 oz bars and my rare earth magnet is about 1/4 the size of these bars and it slides off quite fast at a 45 degree angle but not as fast as plastic.
it does not slide as slow as your magnet but my magnet is 1/4 the size of each of these 1 oz bars.
should i be worried? they weigh in at 31.1g correct weight and i've also done the sound test.
The magnet test is not very accurate, so I would not be too concerned in this case. It is harder to test 1oz bars, given that they are quite a bit smaller.
Words to the wise Ultrasonic Thickness Meter and a caliper. It WLL flag out any lead core or any copper/lead alloy that mimics silver's diamagnetic and density properties. It analyze through the whole length of the metal.
Thanks for the video upload. Sorry to see that you have a fake 100 oz bar. Does that mean you got ripped off? Did the police catch the guy? Or else where may I ask did you get the fake bar from? Thanks.
so did engelhard ripped you off on the other 100 oz bar?
Can you just weigh them? isnt lead going to weigh a lot more when they are the same shape?
nice video
Did you cut it in half?
If there is a flat surface, an ultrasonic thickness gauge would detect that. For gold, checking the weight and dimensions (or using a Fisch detector, which simplifies the process) should catch a 14K item that is 24K plated.
AboutAg nice
They'll slide fast like on plastic. On the other hand - You're not in doubt when you first have had some neodyms in your hand. Yeah, you probably said that for fun ;)
What you however need to be aware of is that many copper (rich alloys) will brake the magnet almost as much. The risk of a silver plated copper bar is probably very small though. And it'll be slightly bigger for a given size. If noticeable without measuring however I cannot say for sure.