Question about the ball-bearing industry

Okay, so I'm scoping out bargain-basement spindle bearings for my CNC project, and I'm trying to get spec data for the various options out there. Is it just me, or is the bearing industry super coy about who/what/where is actually making the products? As best I can tell, almost every maker uses a cryptic three-letter-acronym, and is owned by either SKF, Barden, or Timken (or the Chinese government), with two competing naming systems for the same 'standard' bearing products covering all of these. I think they were all independent concerns at one time, but conglomerated during the Rust Belt decline decades ago, which makes it rather complicated to figure out exactly what spec applies to which bearing when looking at new-old-stock options. It just seems strange & confusing to keep all these storied old industry brand names around, making the same standardized components, with the same part numbers, all owned by the same board of directors.

At the ABEC7/P4 precision level, should all the various options out there have essentially the same specs (load/speed) regardless of who is making them? That is to say, could I use a modern SKF spec sheet to look up data for an old 7200-series or 6200-series Fafnir or NTN bearing, and be reasonably sure of the numbers I see?

TCB

For those three, yes. The order of quality is the order of mentioning. But I wouldn't be hesitant about using any of those brands. Korean or Chinese, I would pass.

barnbwt said:

At the ABEC7/P4 precision level, should all the various options out there have essentially the same specs (load/speed) regardless of who is making them? That is to say, could I use a modern SKF spec sheet to look up data for an old 7200-series or 6200-series Fafnir or NTN bearing, and be reasonably sure of the numbers I see?

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I would guess that the best way to be sure is to email/contact the bearing maker and make sure you're getting what you need. I only use FAG and Nachi bearings and before buying, I email them to make sure I'm getting what I need for the application. FAG is really good about answering questions - you might try it because Abec 7's are going to cost you if you make a mistake.

I'd buy American maybe German but no China bearings for me. To many American tools now are burning out bearings made in China now.

There is a lot of standardization in the bearing industry. That is a good thing, it increases competition and brings down prices. If every application used a different bearing, they would be hopelessly expensive and harder to find replacements for. Part numbers are also very close from brand to brand. One company might use 2RS for double sealed, and another company might use SS. You can ascertain that from their online catalogs. Bearings are not all made by a few makers, and quality is NOT the same from brand to brand. Chinese ABEC7 bearings can often be cut easily with a file and are total junk, not all of them, mind you. One thing for sure. A super deal is likely to be cheap junk bearings unless you are buying NOS on eBay or something similar. Same part number does not mean equal quality. 7200 and 6200 bearings are common and plentiful. You can use an old chart to spec them, but why not use the current one? On bearings made in the US, Europe, and Japan you can believe the specs. On the others all you can do is hope...

Edit: Bearing specs, the long versions, are tedious and boring. But that is where the ifs, ands, and buts come out. Speed is tempered by loading and by temperature, life by shock loading, vibration, and proper mounting. Before you decide on a suitable candidate, read the entire specs and understand what they mean.

Worked at a bearing retailer, Asian 6202 rs- generic common bearings were less than .50 cents a piece. I imagine a reputable maker has more than that in the box.

LOL, I wasn't seriously considering Chinese super-precision bearings (assuming they exist; I didn't see any even claiming to be P4/ABEC7), but they are obviously a power-player in the industry so I mentioned them.

"There is a lot of standardization in the bearing industry. That is a good thing..."
That's pretty much what I concluded; standardized bearings are basically a commodity with no truly differentiating features or quality, short of fraudulent representation which is obviously a concern (I've heard of knock-off bearings that ship out of China in SKF boxes & the like). But this fact is somewhat obscured by the plethora of manufacturers, as well as the insistence in many online forums that certains brands are "good to go" while others are suspect; from what I can tell this variation mostly plagues the lower-grade bearing class that doesn't seem to focus on verified ratings/tolerance so much (like automotive bearings, for example) and incorporates additional features like seals. I wanted to ask to make sure of my impression, though, just in case Bardens were an expecially good deal for those who could afford them, or something. Doesn't seem to be the case, especially considering I'm buying new-old-stock & won't be worrying about warranties or distributors.

Bearings are not all made by a few makers, and quality is NOT the same from brand to brand.

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It sure seems like the dozen or so common nameplates all report to the same three or four makers (NTN & Koyo to SKF, Fafnir to Timken, etc.) are the standardized products from these various branches really so diverse that some names are to be avoided? Is bearing quality plant-dependent to the extent within these nameplates as well? I figure that like anything, it depends on management oversight, and so these mid-eighties vintage Fafnir & Barden bearings I'm looking at were likely the products of reliably professional manufacture. The confusing part is applicable specs, though; it's not like I'll find a vintage sales manual with the speed & load ratings for this particular run of bearings, I'll have to rely on the current figures for the supposed drop-in equivalent (in this case, 7209 & 6209 P4 class bearings). That assumption is complicated by the likelihood that bearing production & inspection have changed (improved one hopes) over the decades.

I still think it seems like a funny industry quirk to have so many names inside the same organizations making the same things. I suppose motor oil & to a greater extent gasoline brands are sort of like that (producing products within a tightly defined spec, while trying to compete with each other on more than pure cost)

At any rate, I'm sure I'll be happy with US-made P4/ABEC7 spindle bearings for the low-low price of 210$; I think it'd be well over a grand for new-manufacture. I'm also sure they'll last forever at my load/speed levels, lol (4000rpm max vs ~15000rpm rated)

TCB

One thing to watch for with NOS double sealed or double shielded bearings is that grease can dry up in storage, and could cause the bearings to die an early death in service. On one side sealed and open bearings you can easily clean them up and re-lubricate them. Your precision bearings are not likely permanently lubricated.

The precision rating is important. When I changed out the spindle bearings on my lathe the same bearing number could be had as a wheel bearing for a car but not at the precision rating. P5.

For a spindle bearing project the bearings are a place to spend money to get the highest precision you can find.

Bob Korves said:

One thing to watch for with NOS double sealed or double shielded bearings is that grease can dry up in storage, and could cause the bearings to die an early death in service. On one side sealed and open bearings you can easily clean them up and re-lubricate them. Your precision bearings are not likely permanently lubricated.

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These are open bearings; their only enemy is rust and abuse