Ball bearing quality

[burnrider]

Before a world wide economy, bearing shops stocked bearings good for almost any use. High quality was almost standard. Today they can be made anywhere under familiar names at lower grades.

I found some engineering standards. ie CR3 (a clearance tolerance for certain applications) or ABEC1 (another standard for new construction). Doesn't really identify bearing longevity related to metal alloys used in their construction.
The only standards I considered were dynamic and static force numbers for bearing rating. Knowing these figures is a least a starting point.

Question is, how do you (HM members) identify the level of bearing quality you want to purchase, so you can use it again?

 

[Ray C]

I don't re-use bearings. In my case, I'm building a turbine jet engine (a pet project) so I identify the size/type needed (often silicon based or very hard chrome) and buy them wherever I can. At 120,000 RPM, I buy the balls individually in packs of 10 and weigh/measure them -and have never found one to vary -at all! But even in other aspects of the shop, most average bearings will do. For your crank handles on equipment, it doesn't make a difference. For the surface grinder and mill spindle... those are one-shot deals and don't get reused for other things. I've never had to replace them but if I did, I'd see about the vendor's return policy before making a purchase.



EDIT: I love that picture of your dog. Puts a smile on my face every time I see it.

Before a world wide economy, bearing shops stocked bearings good for almost any use. High quality was almost standard. Today they can be made anywhere under familiar names at lower grades.

I found some engineering standards. ie CR3 (a clearance tolerance for certain applications) or ABEC1 (another standard for new construction). Doesn't really identify bearing longevity related to metal alloys used in their construction.
The only standards I considered were dynamic and static force numbers for bearing rating. Knowing these figures is a least a starting point.

Question is, how do you (HM members) identify the level of bearing quality you want to purchase, so you can use it again?

 

[burnrider]

I'm building a turbine jet engine (a pet project) so I identify the size/type needed (often silicon based or very hard chrome) and buy them wherever I can.

In your experience, size and type (bearing number) offers the same quality no matter who sources it?

 

[Ray C]

I really can't tell because what I'm doing is very experimental in nature. I'm ordering the balls based on material, diameter and temperature rating. I'm experimenting with different weights being spun at different orbital diameters within a tightly fitting recess that is part of my bearing design (which by the way, double serves as the oil pump -pretty slick, huh?). It wouldn't be fair for me to say one manufacturer is better than another -because they all seem the same and all have acted the way I would predict. -And in some cases that means explode/disintegrate. All I can really say for sure, is that if I mic a batch and weigh them on highly-precision beam balances, I can't measure any differences -no matter who I buy them from. BTW: a pack of 10 balls (depending on diameter and manufacturer) is running between 30 to 80 bucks for ceramic. Chrome are cheap... -pennies.

For less crazy uses, I use packaged bearings for balance mechanisms, bandsaw blade guides, homemade shop equipment... basic stuff that just doesn't really matter. If I had to replace the bearings of something important like (heaven forbid) the lathe spindle, mill quill or surface grinder, I'd lean toward a name brand or off-brand provided they had a decent return/exchange policy.

In your experience, size and type (bearing number) offers the same quality no matter who sources it?

 

[DMS]

The bearing specifications (ABEC, etc) are all about dimensional accuracy. Cost rises rapidly with increased accuracy. In general, unrated bearings are probably fine for things that are not critical. I like to stick with at least ABEC 1. For higher speeds, you generally want better accuracy. If you are making a spindle, you probably want at least ABEC3 or higher, 7 or 9 if you can afford them. I have found that all the name brands I have purchased (SFK, Nachi, some others) gave me what I payed for. I think the Nachi's were made in Japan, and the SFKs were made somewhere in Europe. I would say, buy a good brand, and the spec you need, and you should be safe, regardless of where they were manufactured. If you are having trouble finding a particular bearing, I had good luck with Callahan bearing. They didn't have what I needed in stock, but had it shipped directly from the manufacturer to me in short order.

 

[tarmo120]

I believe you are talking about SKF Bearings.
SKF is one of the biggest bearing manufacturer in Europe.
Actually most car dealers here use SKF bearings, they are really good quality.

 

[dwdw47]

I have used SKF for more years than I want to say. The quality has been there so far.
I use China bearings in electric motors (C3) and they work very well. Many bearings are made in Japan and they are fine, they follow the industry standards.
In 2001-2003 I did a test replaced the more expensive and high quality SKF bearings with a very economical both side sealed China bearing in the form rollers in a Baker Perkins high speed press. The other Baker Perkins press used SKF manufactured in no specific Country.
That was replacing over 160 bearings for a 2 year test, each bearing was documented and run 16,736 hrs. Varying the RPM 1200 to 2000.
Ending of the test there were 5 bearings selected from the same position from each press and dissected after a run-out and radial play tests were done, internal wear was very similar and no failure of ether test press bearing.
The test was to conserve costs as the SKF being $57.00ea and the China bearing $12.00ea.
I set up a re-manufacturing program to be able to buy all bearings OEM.
The reduced cost was astronomical!
Before my test I was a firm believer in the SKF as superior. The results were almost identical.
There was no test on the Precision print cylinder bearings as there is was no replacement other than SKF and a few Timken at that time Precision Class 6 copper dotted for maximum run-out.
I still try to use the manufacturers spec'd bearing when doing precision spindle and arbor rebuilding.
This is my 2cents.Hope no-one fell a sleep!
Thank You
dwdw47