I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?


i

I've used the inexpensive bearings from Ebay for some motors and for cart
wheel bearings - they have been good bearings, and most were made in places
other than china (like Russia) - so far no problems. On the other hand, the
cart (a harbor freight hydraulic lift cart) had bearings in it that were not
hardened - they sure didn't last very well.

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?


i

Ignoramus23515 wrote:
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?


i



The difference is in the metal, the heat treating, and the precision of
the machining and grinding operations to make the bearing.

The Chinese bearings seem in most part to lack the quality in the metal
they are made of. They seem to be a little softer and thus wear much
faster. 252100 is the usual metal used to make bearings. I would imagine
though that they do make some good quality bearings but you can only
tell that after you install them.

I have a pile of bearings I have to install back in a machine
transmission I have apart. All these bearings are lubricated by a drip
oil system and pump like most larger lathes. All the drip oil lines must
be lined up so that each bearing gets oil, as well as the other gearing.
All theses bearings are SKF brand. The one bearing I need is obsolete
and I had to order a similar bearing with a wider inner race that will
have to be machined down. They are roller bearings and the inner race is
removable. It has a small flange on the one side and because of that it
costs twice as much, 185 bucks vs. 70 without the flange.

I use a bearing heater to install the bearings. A cheap crock pot works
well to evenly heat the bearings up to 250 degrees. I use it with a
thermometer. You start to lose the temper in the bearing metal at
300degrees.

John

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?


i


Thanks for the kind words!

I use cheap bearings all the time for applications that don't have high
demand. Often my stuff is slow, the bearings are more robust than needed or
the bearings are easy to replace. The savings add up to a LOT!!! However,
for high demand, high speed, high precision (Barden) or bearings that are
hard to get at or hard to replace, I put in the best I can get.

I just installed two import 1" pillow blocks that were $6 each. The
domestic were $30. I can get at them easily and the rotation is 33 rpm with
a 100 lb. load. I probably spend $2k/yr. on bearings and half are imports.

Ignoramus23515 wrote:

I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

i

Here is an interesting bit of information, you can draw your own
conclusions from it:

A few years ago I purchased one of the cheap Harbor Freight 4x6 H/V
bandsaws. I noted two interesting thins about this surprisingly decent
saw, first was that it was made in Taiwan, not mainland China, and
second all the ball bearings on it including the blade guide bearings
are marked NTN Japan.

"Pete C." wrote in message
ster.com...

Ignoramus23515 wrote:

I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

i

Here is an interesting bit of information, you can draw your own
conclusions from it:

A few years ago I purchased one of the cheap Harbor Freight 4x6 H/V
bandsaws. I noted two interesting thins about this surprisingly decent
saw, first was that it was made in Taiwan, not mainland China, and
second all the ball bearings on it including the blade guide bearings
are marked NTN Japan.

Take it for what it costs,

electric motor bearings have c3 rating or something like that most from the
local bearing house with name brand are that. Most cheap ones don't even
seem to have the normal markings of number, brand, and country.

For some applications there are precision bearings which are picked out out
of batches of normal bearings. I doubt that would be necessary for the
motor. At least that is what I have heard from guys in the business of
buying used machinery.


Fran

On 2010-02-21, fran...123 wrote:

"Pete C." wrote in message
ster.com...

Ignoramus23515 wrote:

I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

i

Here is an interesting bit of information, you can draw your own
conclusions from it:

A few years ago I purchased one of the cheap Harbor Freight 4x6 H/V
bandsaws. I noted two interesting thins about this surprisingly decent
saw, first was that it was made in Taiwan, not mainland China, and
second all the ball bearings on it including the blade guide bearings
are marked NTN Japan.

Take it for what it costs,

electric motor bearings have c3 rating or something like that most from the
local bearing house with name brand are that. Most cheap ones don't even
seem to have the normal markings of number, brand, and country.

For some applications there are precision bearings which are picked out out
of batches of normal bearings. I doubt that would be necessary for the
motor. At least that is what I have heard from guys in the business of
buying used machinery.

I thought that regular ABEC-1 should be good for regular electric
motors. Is that right?

i

On Feb 21, 7:29*pm, Ignoramus15530 ignoramus15...@NOSPAM.
15530.invalid wrote:
On 2010-02-21, fran...123 wrote:





"Pete C." wrote in message
nster.com...

Ignoramus23515 wrote:

I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

i

Here is an interesting bit of information, you can draw your own
conclusions from it:

A few years ago I purchased one of the cheap Harbor Freight 4x6 H/V
bandsaws. I noted two interesting thins about this surprisingly decent
saw, first was that it was made in Taiwan, not mainland China, and
second all the ball bearings on it including the blade guide bearings
are marked NTN Japan.

Take it for what it costs,

electric motor bearings have c3 rating or something like that *most from the
local bearing house with name brand are that. *Most *cheap ones don't even
seem to have the normal markings of number, brand, and country.

For some applications there are precision bearings which are picked out out
of batches of normal bearings. *I doubt that would be necessary for the
motor. *At least that is what I have heard from guys in the business of
buying used machinery.

I thought that regular ABEC-1 should be good for regular electric
motors. Is that right?

i

I believe there is an electric motor grade for bearings in addition to
the ABEC grades. They are graded for noise in addition to the size
specs.



Dan

On 2010-02-22, wrote:
I thought that regular ABEC-1 should be good for regular electric
motors. Is that right?
I believe there is an electric motor grade for bearings in addition to
the ABEC grades. They are graded for noise in addition to the size
specs.

Thanks Dan, I did not know about the noise test. I put regular ABEC-1
FAG bearings in a motor on my lathe, that was noisy previously
(squealing). Now it is quiet, with only noise coming from a fan inside
the motor. Note that it is only a 1800 RPM motor.

i

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

In my experience, you can NOT save money by buying cheap bearings!
The labour cost of replacing bearings is far greater than the cost
difference between quality bearings like SKF and Chinese rubbish. The
shorter lifetime of the cheap bearings causes your total costs to increase.

On 2010-02-20, Grumpy wrote:

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

In my experience, you can NOT save money by buying cheap bearings!
The labour cost of replacing bearings is far greater than the cost
difference between quality bearings like SKF and Chinese rubbish. The
shorter lifetime of the cheap bearings causes your total costs to increase.



So, what kind of experience did you have?

i

"Ignoramus30516" wrote in message
...
On 2010-02-20, Grumpy wrote:

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

In my experience, you can NOT save money by buying cheap bearings!
The labour cost of replacing bearings is far greater than the cost
difference between quality bearings like SKF and Chinese rubbish. The
shorter lifetime of the cheap bearings causes your total costs to
increase.



So, what kind of experience did you have?



Various Engineering positions,including Engineering Manager,Chief Engineer
and Packaging Engineering
Manager since 1973.

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

Generally, if they go through the trouble of getting an ABEC rating, they
are decent. If not, then you never know what you are going to wind up with.
That's my experience anyhow.
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill

V8013-R

On Mon, 22 Feb 2010 09:21:05 -0500, "Joe AutoDrill"
wrote:

"Ignoramus23515" wrote in message
...
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

Generally, if they go through the trouble of getting an ABEC rating, they
are decent. If not, then you never know what you are going to wind up with.
That's my experience anyhow.

Is there actually tracability in the ABEC rating or is it "self
certified"?

Eg. UL markings have an associated file number which you can use to
check out the certification (I have found 'discrepancies' from
offshore suppliers more than once..)

CE (and RoHS) stickers can be had for next to nothing at markets in
China..

Generally, if they go through the trouble of getting an ABEC rating, they
are decent. If not, then you never know what you are going to wind up
with.
That's my experience anyhow.

Is there actually tracability in the ABEC rating or is it "self
certified"?

Not sure... It could simply be a fact that if they know what an ABEC rating
is, they are smart enough to know to harden the races and balls, etc.
....Then again, my bearing applications are not nearly as critical as others
so keep that in mind.

A bearing ona drill press head is not the same as a bearing on a CAT40
CNC - even if they are, for some freak of nature's reason, the same size.
--


Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill

V8013-R

On Mon, 22 Feb 2010 09:36:03 -0500, Spehro Pefhany
wrote:

On Mon, 22 Feb 2010 09:21:05 -0500, "Joe AutoDrill"
wrote:



Generally, if they go through the trouble of getting an ABEC rating, they
are decent. If not, then you never know what you are going to wind up with.
That's my experience anyhow.

Is there actually tracability in the ABEC rating or is it "self
certified"?


I think the latter, or if there is traceability it's not enforced.
There are plenty of "ABEC 9" skateboard and rollerblade bearings on
ebay for less than a buck apiece.

--
Ned Simmons

I think the latter, or if there is traceability it's not enforced.
There are plenty of "ABEC 9" skateboard and rollerblade bearings on
ebay for less than a buck apiece.

If they *are* ABEC9, they won't be after the first use.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill

V8013-R

Ignoramus23515 wrote:
I want to know how much worse are the cheap chinese bearings compared
to the alternative. For example, compare ebay item 150403737068
($4.76) with McMaster item 5972K353 (20.26 each). Both are 6306 double
shielded bearings (for the motor in my Clausing lathe).

For the replacement, I bought the McMaster bearings, first because I
could have them next day for the weekend, and second, because I was
assured of their quality. I think that McMaster ones are FAG brand.

Does anyone know in what ways are the cheap bearings inferior. I
remember how a while ago Tom gave us a good rundown on what makes
cheap wire brushes different from quality ones (use of discardded tire
cord etc). Maybe someone knows enough about bearing quality?

I have limited experience with that size/tyoe, except that I have used
the 203FF chinese bearings in a variety of automotive applications for
years (decades?) with no failures that I can recall.
Some years back - 2001? - I was out of town at a race and needed to
replace the front wheel bearings on my road race Mazda. all I could find
were Chinese generics, so that's what i settled for. figured they
would get me through the weekend.
I bought some Timkens when I got back, but those Chinese bearings
are still on that car, and I still race it.