How to Spot Counterfeit/Fake Bearings?

[Halcohead]

Do any of you guys have any good advice for methods to spot counterfeit or fake bearings? I understand that installing and running the bearing in its intended application is a safe bet, but often this invalidates return policies, and can involve painful reinstallation. Are there any checks one can do using standard machine shop measuring tools before installation, for example on high-grade (ABEC 7/P4) angular contact bearings?

Specifically, I am looking to purchase six 30x62x15mm P4 grade 60* angular contact ball bearings (as manufactured by Barden, Nachi, SKF, NTN, NSK, Fafnir, etc), and eBay has a seller (raspartsales) who stocks these for $89 a piece, as opposed to $170-$450 a piece from the more reputable bearing suppliers I work with. That price differential seems large enough to be worth investigating. There are angular contact bearings on ebay that ship directly from Hong Kong which are cheaper, but that seems a bit too suspicious to me.

Due to the pain of removing/installing the particular bearings I am dealing with, I will probably go with the reputable supplier (not eBay), however this seems like an important skill to have for anyone who works with or on precision rotary assemblies.

 

[machtool]

The one easy thing you could do is place it on Granite and run it under your very best indicator. In P4 the thickness variation of the race should be 2 or 2.5 microns. If they haven’t gotten the races parallel, all bets are off, where they managed to grind the races.

As I’m reading the SKF catalog correctly, both the inner and outer should be within that thickness tolerance. Don’t be alarmed if they appear undersize for thickness. There quite a large allowance for overall thickness. But they must be parallel and the same, inner to outer. You normally have to flip them from back to face to measure inner and outer.

Phil.

 

[adama]

If your that worried they should be able to supply documentation with them, similar to a material certificate. Ergo there traceable back to the manufacturer. If its second hand stock being sold off all bets are off.

 

[Limy Sami]

While agreeing with what others have said about traceablity and measuring - etc etc
General appearance and ''feel'' can give the fakes away - hard to describe but if you put mostr fakes next to genuine it's pretty obvious.

But I agree with the main point, unless it's certified, all bets are off.

 

[wippin' boy]

they have a slightly less salty taste

 

[RC99]

Where is the evidence of counterfeit bearings in the first place? Last I heard one of the stories of counterfeit bearings was a fake itself...

 

[machtool]

Where is the evidence of counterfeit bearings in the first place? Last I heard one of the stories of counterfeit bearings was a fake itself...

That’s a more than fair point. If I was a counterfeiter. I wouldn’t be starting 30-62-15 X 60degree high thrust angular contact P4 bearings.
I’d beconcentrating on the in-line skate market.

http://www.stopfakebearings.com/#/start

You would think a site like that would help our O.P Halco, identify a fake bearing.But not one word there how to identify a fake bearing. But plenty of links to factory authorized dealers.

Has any one worked out where this WBA World Bearing Association comes from, Anyone have a physical address?

Personally I think that’s a corporate marketing exercise, to keep you into factory distributors, and not bearing resellers.

Phil.

 

[DDoug]

I replaced the wheel bearing in my shop truck last year, name brand, made in china.

Had to replace them again last week, bad steel (it appears) as 2 spots developed in the outer race.

Brand name, feels good, no way to spot a bad spot in the steel (for me under the shade tree anyway).

It's not so much "fake" as pooor quality.

Certified ? Traceability ?

The xerox machine will give you all the "papers" you americans require......

 

[Steveo]

I talked to a THK rep about a year ago and he said about 50% of warranty claims to them involve conterfeit products. A customer of mine who imports bearings from China was asking his supplier how much it would cost to get his logo on the bearings and the supplier said 'no charge for your logo, NTN SKF, whatever you want.'

 

[USMCPOP]

If they come with an instruction sheet like this, I'd be suspicious.

 

[SteveF]

That’s a more than fair point. If I was a counterfeiter. I wouldn’t be starting 30-62-15 X 60degree high thrust angular contact P4 bearings.
I’d beconcentrating on the in-line skate market.

Then again, if a Chinese company is already making bearings and has a lot rejected by internal QC or the buyer's QC, this is a great way to get marginal bearings out the door.

Steve

 

[acme thread]

In the early 70's My wife got a job working in a TRW warehouse, One of her first jobs , Was taking Japanese
automotive bearings out of the Japanese Boxes, and repackaging in TRW boxes.
All those companies do it.
My brother worked in a GM plant making driveshaft components, He told me the needle bearings used in universal
joints, came in 5 gal. plastic buckets, they dumped them in a hopper, and the machine sprayed them into a finished bearing cup, along with a wad of grease, then went down a conveyor like little soldiers off to war.
Dave [acme thread]

 

[Halcohead]

The suggestion of indicating front/back parallelism seems like a good place to start.

I agree that it is a bit too convenient for a manufacturer to be able to slack on QC, an then claim any bad lots are "really good counterfeits". I was surprised at how hard it's been to find documentation from OEMs regarding how one can spot a fake bearing. That said, I have read enough reputable stories to believe counterfeits aren't a real problem.