Wheel bearing - pre-load & run in.

"Phil W Lee" wrote in message
...
AMuzi considered Tue, 09 Sep 2014 09:32:10 -0500
the perfect time to write:

On 9/9/2014 6:35 AM, John B. Slocomb wrote:
On Mon, 08 Sep 2014 14:16:43 +0100, Phil W Lee
wrote:

"Ian Field" considered Sat, 6 Sep
2014 20:14:53 +0100 the perfect time to write:



wrote in message
...
yes and no.....thin plated bearings...gray bearings go with worn/used
hubs.

Grade 5 go with above average hubs or as new hubs...grade 5 runs new
longer than gray bearings.

The new ball bearings were very shiny when I put them in, and sort of
grey
when I examined them a few days later to see why the hub hadn't stayed
adjusted for long.

All the shinyness had become little shiny flecks in the grease.

That would be evidence for them being plated, not through-hardened.

As you found out, under stress, a plated ball will shed it's plating,
at which point it becomes birdshot in grinding paste.


Does someone actually make plated bearings for sale to the public?
My uncle worked at a bearing factory and he once mentioned that they
were making some gold plated bearings for NASA some sort of space
thingy, but I don't believe I ever encountered a plated "ball bearing"
for general use.


I think that's an urban myth. People see metal flecks from
spalled bearings and mating surfaces and assume it's chrome
peeling of the balls.

Not when you can actually peel the plating off the damaged balls in
chunks with a fingernail.

The one's I bought were a bit more ****ed than that by the time I stripped
the hub again to see what was going on.

On Fri, 12 Sep 2014 18:13:47 +0100, "Ian Field"
wrote:



"Phil W Lee" wrote in message
.. .
Frank Krygowski considered Mon, 8 Sep 2014
13:42:05 -0700 (PDT) the perfect time to write:

On Monday, September 8, 2014 9:16:43 AM UTC-4, Phil W Lee wrote:
"Ian Field" considered Sat, 6 Sep

2014 20:14:53 +0100 the perfect time to write:

All the shinyness had become little shiny flecks in the grease.

That would be evidence for them being plated, not through-hardened.

As you found out, under stress, a plated ball will shed it's plating,
at which point it becomes birdshot in grinding paste.

I'd have thought it would be essentially impossible to buy soft but plated
steel balls, when one asked for ball bearings.

Sadly not.
I learned my lesson in my early teens, when inspecting a bearing (and
I can't remember what it came out of) revealed shiny plating which on
the balls which were damaged, could be peeled off, in large (and
sharp, which may explain why I remember it) flakes.

Back then it was probably an extremely rare case of fake goods - now we're
living in the age of cheap Chinese knock-offs for pretty much everything!

But seemingly that is what people want. Harbor Freight, a company that
originated with a bloke importing a cargo container full of the
cheapest Chinese stuff that he could locate, is now a Billion dollar
business.... doing the same thing. Walmart, the largest
merchandiser... same thing.
--
Cheers,

John B.

On Fri, 12 Sep 2014 15:12:08 +0100, Phil W Lee
wrote:

Frank Krygowski considered Mon, 8 Sep 2014
13:42:05 -0700 (PDT) the perfect time to write:

On Monday, September 8, 2014 9:16:43 AM UTC-4, Phil W Lee wrote:
"Ian Field" considered Sat, 6 Sep

2014 20:14:53 +0100 the perfect time to write:

All the shinyness had become little shiny flecks in the grease.

That would be evidence for them being plated, not through-hardened.

As you found out, under stress, a plated ball will shed it's plating,
at which point it becomes birdshot in grinding paste.

I'd have thought it would be essentially impossible to buy soft but plated steel balls, when one asked for ball bearings.

Sadly not.
I learned my lesson in my early teens, when inspecting a bearing (and
I can't remember what it came out of) revealed shiny plating which on
the balls which were damaged, could be peeled off, in large (and
sharp, which may explain why I remember it) flakes.
Admittedly, for some applications (drawer sliders, for example), where
you need smooth running but only very light load bearing capability
and very little wear resistance, through hardening would be a wasted
expense, but a very tiny one.

But there's always a market for a cheaper alternative to anything, and
someone unscrupulous who will sell it in place of the decent quality
item.
It's even worse these days, because far to many engineering businesses
have bean-counters in control instead of people who know what they are
doing..

Sorry, but I don't believe I've ever had that experience with any of
the reputable bearing manufacturers. Nor for that matter, have I ever
heard of it happening.

I suspect that the practice is restricted to the cheap stuff which is
aimed directly at the market that's main criteria is "buy cheap .. who
cares about quality"
--
Cheers,

John B.

"The major players, INA/FAG, SKF and Timken all manufacture in China and have top notch quality control, so those bearings should be the same quality as those made here and in Europe. Timken is the only major I know of that imports Chinese bearings, so if you see an SKF or FAG with Chinese markings on it, be suspect. It would also be a good idea to buy from a reputable supplier since there are a lot of counterfeit bearings coming out of Asia. FAG and SKF just confiscated 40 tons of bearings from a German distributor."

http://www.practicalmachinist.com/vb...parison-92315/

SEARCH: CHINESE BALL BEARING QUALITY

From 15+ years ago, there are bags in stock wih grey surfaced bearings and grade 25's. No problems with the grey's.
Buy from a quality shop selling quality bearings. I found an industrial store selling me greys at 25 prices plus.
The extent of my equipment made in China is depressing. I followed the process since the mid 60's. moderate price levels bring in top quality equipment.

wrote in message
...


"The major players, INA/FAG, SKF and Timken all manufacture in China and
have top notch quality control, so those bearings should be the same
quality as those made here and in Europe. Timken is the only major I know
of that imports Chinese bearings, so if you see an SKF or FAG with Chinese
markings on it, be suspect. It would also be a good idea to buy from a
reputable supplier since there are a lot of counterfeit bearings coming
out of Asia.

Presumably Chinese parts manufactured for Western companies are subject to
Western quality controls.

But the Chinese can knock up a manufacturing project surprisingly quickly,
and vanish only to re-appear somewhere else with a different name just as
quickly.

I've heard that Some Chinese printed circuit factories can design a layout,
screen and etch, and have a stack of drilled and finished PCBs within an
hour.

If you design a circuit for a hobby magazine, and someone in China likes the
idea - it can be on Western shelves in a couple of weeks.