Luck buying legitimate parts on Amazon?

Discussion in 'General Electronics Chat' started by MrSoftware, Jan 18, 2016.

  1. MrSoftware

    Thread Starter Member

    Oct 29, 2013
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    Has anyone picked up counterfeit parts on Amazon? I found some with a price too good to be true, so I'm suspicious..

    I've been checking Amazon first lately because with Prime I can have it in 2-days for free, cheaper and faster than Digikey, Mouser, etc.. for small orders. I'm shopping for beefy n-channel MOSFETs and I stumbled across these, IRF3205PBF 10-pieces for $3.29 with free shipping. At this quantity Digikey gets $1.97 /ea and Mouser gets $1.86/ea, plus shipping, so naturally I suspect the Amazon listing is counterfeit parts. I guess it's possible that someone ended up with a pile of devices with no use and is just dumping them, but somehow I suspect that's not the case. ;)
     
  2. WBahn

    Moderator

    Mar 31, 2012
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    I think your suspicions are warranted. Unless you can vet the supplier, you are probably taking a gamble. I don't know the probabilities (and I'm sure they vary all over the place), but I suspect that there are a lot of legitimate surplus stock that is sold on Amazon, Ebay, and elsewhere. But loads of counterfeit crap, too.
     
  3. dl324

    Distinguished Member

    Mar 30, 2015
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    I have purchased counterfeit items on Amazon. Not electronic parts, which I won't buy on Amazon or any eBay store/auction if it appears to be their business.

    In the past, I've purchased many components on eBay; but they were almost exclusively from people who had varying stock and were clearly selling things they bought at surplus liquidations. But that was a decade ago before counterfeiting from China was such a big problem.

    If the price is too good to be true, it probably is; especially if the parts are coming from China.
     
  4. WBahn

    Moderator

    Mar 31, 2012
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    You might compare the Amazon prices to Digikey's high volume prices (or other volume distributor).

    Just throwing numbers together, if you had a product and you needed 400 widgets and they were $2 each at that quantity but were $1 each in a quantity of 1000 widgets, if your budget allowed you to only spend $1.75 for each widget, then you can only spend $700 for the 400 that you need. But you could meet that target by buying the 1000 widgets for $1000 and then dumping the excess 600 for $300 (or just 50 cents a piece). You would probably sell those as a lot to a surplus house who might then mark them up 30% and sell them for 65 cents a piece.

    Stuff like that happens all the time.
     
  5. MrSoftware

    Thread Starter Member

    Oct 29, 2013
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    Looking at this seller, they don't seem to specialize in semiconductor devices so I guess it's not unbelievable that this might be surplus they picked up for cheap. But it ships from Hongkong... For that price I might have to pick some up just to study and see if I can determine if they are real or not to satisfy my curiosity.
     
  6. dl324

    Distinguished Member

    Mar 30, 2015
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    When I buy parts, I buy in at least qty 100. Many times buying a full reel of 5000 resistors was cheaper than buying 500-1000.

    Which is why I have many parts available for barter if anyone (in the lower 48) is interested...
     
  7. WBahn

    Moderator

    Mar 31, 2012
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    As an interesting related side story, the PCB house that I used to use a couple decades ago had a quantity pricing strategy (driven by their panel sizes and the efficiencies associated with using a single panel for an entire design) such that, for some sizes, it actually cost less total dollars to buy 10 boards than it would cost to buy 7. So a couple of times I needed 8 boards for a project and I bought 10 knowing that the other two would end up sitting in a box for years until they finally got thrown away. But one of those times really worked out for me because we needed to make some general purpose drive electronics and I wanted a couple for my home lab, so I got the boards for free and the parts I got at the reduced prices for just the using just the approach described above. All of this with my employer's knowledge and blessing -- everything was priced so that the total cost of the eight units the company needed was 10% less than it would have been had they just bought what they needed and everyone was happy.
     
  8. dannyf

    Well-Known Member

    Sep 13, 2015
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    When buying from Amazon and eBay or places like that, you should assume it being counterfeit.

    You will be much happier that way.
     
  9. dl324

    Distinguished Member

    Mar 30, 2015
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    A problem with parts manufactured in China is that they will often reduce quality over time and in a way that even legitimate companies will be unable to detect unless they do incoming QA on 100% of the product; which is an expensive proposition.

    There shops in China that only sell counterfeit product. Presumably to people who are going to resell to unsuspecting consumers at maximum profit.

    Even companies who hire investigators to root out counterfeits of their products are being scammed. One such investigator had started up several factories to manufacture shoddy counterfeits of products from the companies he was hired by. He would turn over the counterfeits for the bounty offered by his clients.
     
  10. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    "fake" parts are everywhere on the typical "Amazon/Ebay",etc...
    If you are worried and want quality parts then you should be buying from reputable suppliers like Digikey/Mouser/Newark/Farnell... simple as that..
    If you are too cheap to do so then.....well..

    Quality components are cheap.. compared to what "could" happen..
     
  11. WBahn

    Moderator

    Mar 31, 2012
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    If I'm buying parts for a hobby project, I might (okay, very possibly would) take the chance for a significant savings. But saving 80% on a dollar scale item isn't significant. Saving 50% on a several hundred dollar item might be.

    When I started working for a company (instead of doing projects as a student) I had to shift gears from the mindset that spending hours of my relatively worthless time finding the lowest available prices on components to realizing that my time had value to my employer and that paying the one-off prices that Digikey commanded (which were significantly higher proportionately than they are today) was the economical route. Digikey almost always had what I needed, they had it in stock, and they would sell me just one of them. So if they had it in their catalog, they got the business. The savings in time more than paid for the higher cost and shipping expense (though, of course, I would consolidate as many items/orders as possible into a single shipment).

    That has largely carried over into my hobby life since. If buying from Digikey saves me an hour of time trying to save a few bucks, that is an hour of time I can choose to work on a paying project that makes up for the extra cost in spades. Now, if I were a poor grad student once more, my approach would most certainly be different.
     
  12. SLK001

    Well-Known Member

    Nov 29, 2011
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    Amazon is only a front, just like eBay. If you want good parts, buy from legitimate distributors.
     
  13. dl324

    Distinguished Member

    Mar 30, 2015
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    One of these days eBay and Amazon will get smart and realize that not making a concerted effort to drop counterfeiters is hurting their business.

    My family buys a lot of stuff from Amazon where getting a counterfeit product isn't an issue (screen protectors, phone protectors, etc). I bought 20 mirror finish screen protectors for an smartphone for US$1 (including shipping). They were either counterfeit or a manufacturer who decided to compete with their customer; it didn't matter to me. We had 3 of that particular smartphone and a lifetime supply of screen protectors for a nickel apiece; the brick and mortar stores were selling them for $10 each.
     
  14. ISB123

    Well-Known Member

    May 21, 2014
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    I have few parts ordered from eBay.I'll test them and post the results.
     
  15. Sinus23

    Member

    Sep 7, 2013
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    If y'all;) guys are complaining about prices on Digikey and Mouser. I bought 10 TL074 for about $15 bucks here. This is what happens in a small market.

    So far most of my hobby inventory has been bought through E-bay. First I thought to myself. TI chips cheaper than from the US? lets wait and see since there isn't much of a gamble. $2 lost well OK. But then I though where are those chips manufactured?
     
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