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Standard Catalog Bearing Quality 1

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tc7

Mechanical
Mar 17, 2003
387
Hello all-

How can I determine bearing quality and what ABEC precision level applies to standard catalog bearings?
For instance I am replacing several motor bearings that had double sealed Fafnir numbers which now cross over to #88506. The 88506 is available from NUMEROUS manufacturers, but pricing between say a Timken 88506 and an IKS 88506 are multiples apart, with other manufacturers like an MRC 88506 fall right in the middle. I know these are all good popular companies, but since I have nothing else to judge by, is price a fair representation of quality and ABEC precision? Or is one 88506 equal to any other 88506?

Incidentally, I have spent HOURS seeking information on line and making calls, but since I am not an equipment engineer, I can never get through to the technical bearing people.

Thanks for advising.
Tom



 
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what ABEC precision do you need?

Looks like IKS offers ABEC-1 and 3.

In the US I'd call one of SKF's main numbers. The menu should offer a selection for technical questions. If not, late in the menu an operator should be available to direct your call.

 
Most manufacturers offer ABEC 1 as standard, however all the first world producers are much closer to ABEC 3.

So buy from Fafnir, SKF, FAG, Koyo, NSK or NTN and you will be fine unless this is a specialty application like a machine tool spindle.

For motor applications none of those names will disappoint.
 
In my experience the quality varies significantly between the major brands and the low-cost alternative brands. The best brands greatly exceed the required accuracy according to whatever international standards govern that bearing size. I'd quote factual data but I have only a couple of anecdotal experiences - we changed course immediately and have not had issues since.

It is further clouded by the fact that confirming the source of the low-cost brands gets really hairy, and the illegal knock-off bearings are lower quality still.

In most cases the machine design and track record is based on the performance using the premium brand bearing, and the performance using the low-cost alternative brand can be vastly poorer. At my company we have taken to using an allowable substitute list, so that we might allow SKF, FAG, NTN, NSK, but not just any random brand from the far east or eastern europe.

David
 
In my limited experience, price does roughly correlate to my happiness with a bearing's performance. ... and a { clerk's | salesman's | merchant's } assurance does not.

If a particular application can be satisfied with marbles rolling in a jar lid, then specifying by size alone and allowing unlimited source choice should be okay.

If a particular application caused you to drag out the _thick_ bearing book, then you probably need to use some kind of source control.



Mike Halloran
Pembroke Pines, FL, USA
 
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