Since I found a pair of 7209 Fafnir Abec 7 bearing amongs some of the
stuff I took home recently, I did a little research. Looks like ABEC 7
refers to a very precise grade of bearings that are usable at very
high RPM in machine tool spindles. (this one seems to be good for 22k
RPM, for example). This stuff is god awful expensive, like $300 per
such bearing at McMaster.

At the same time, if you search for ABEC 7 on eBay, you will see a
huge quantity of a buck a dozen "ABEC 7" skateboard or roller skate
bearings.

I have hard times believing that they are really made to such
specs. (or that skateboards need such precision)

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

i

On 2007-10-27, Diamond Dave wrote:
On Sat, 27 Oct 2007 14:40:54 -0500, Ignoramus2057
wrote:

Since I found a pair of 7209 Fafnir Abec 7 bearing amongs some of the
stuff I took home recently, I did a little research. Looks like ABEC 7
refers to a very precise grade of bearings that are usable at very
high RPM in machine tool spindles. (this one seems to be good for 22k
RPM, for example). This stuff is god awful expensive, like $300 per
such bearing at McMaster.

At the same time, if you search for ABEC 7 on eBay, you will see a
huge quantity of a buck a dozen "ABEC 7" skateboard or roller skate
bearings.

I have hard times believing that they are really made to such
specs. (or that skateboards need such precision)

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

Probably more of a lie than clever marketing. I use ABEC-7 bearings in my
Shimano Curado fishing reels and they really are slick. I get them he
http://mikesreelrepair.com/
And they aren't that cheap, but Mike sells them for less than anywhere else I've
found.
As far as I can tell, ABEC-7 bearing are supposed to have ceramic balls/rollers
and I have my doubts about how much shock they could take on a skate board
type use.


Not necessarily, ABEC 7 refers to precision, I think. Mine have steel
balls. I have no doubt they really are abec 7.

I also saw a lot of "ABEC 9" skateboard bearings on eBay, what a B.S.

i

Ignoramus2057 writes:

Are those skateboard bearings really made to ABEC 7?

You can't trust the skate and skateboard manufacturers. From the beginning
they were designing in those bearings way beyond their specific load
limits, putting many 100s of lbs onto 608 bearings. They're children (when
it comes to engineering) marketing to children. Not that they haven't been
very successful commercially in many cases.

Take that premise and run it through eBay, and you've got utter nonsense.

Ignoramus2057 wrote:

At the same time, if you search for ABEC 7 on eBay, you will see a
huge quantity of a buck a dozen "ABEC 7" skateboard or roller skate
bearings.

I have hard times believing that they are really made to such
specs. (or that skateboards need such precision)


I was at a Favnir or SKF class a few years ago. They said they didn't make
an ABEC 1 and a 3 was likely to be a 5 since their goal is to make good
bearings.


Wes

On Oct 27, 12:40 pm, Ignoramus2057
wrote:

I had a long discussion with a particularly stubborn friend of mine
about this very topic.

ABEC 7 is the grade used for machine spindle bearings, and is
obscenely expensive (when the tolerances are held to +/- 0.0001",
you'd kinda expect it to be). Nearly all ABEC 7 bearings I've ever
encountered were tapered roller bearings.
The skateboard manufacturers just use it as a cool name, most skate
bearings are ABEC 3 at best. Most non-engineers aren't aware of the
real system.

Fafnir actually makes both real bearings (I think they're a subsidiary
of Timken now) as well as skate bearings. I have some Fafnir
machinery bearings, they're good stuff. Usually the shields on the
skate bearings are colored a bright color, the ones I have are either
green or red. The equipment bearings have black shields or are
unshielded.

On 2007-10-28, woodworker88 wrote:
On Oct 27, 12:40 pm, Ignoramus2057
wrote:

I had a long discussion with a particularly stubborn friend of mine
about this very topic.

ABEC 7 is the grade used for machine spindle bearings, and is
obscenely expensive (when the tolerances are held to +/- 0.0001",
you'd kinda expect it to be). Nearly all ABEC 7 bearings I've ever
encountered were tapered roller bearings.

The one I have, is a ball bearing. (a pair actually).

The skateboard manufacturers just use it as a cool name, most skate
bearings are ABEC 3 at best. Most non-engineers aren't aware of the
real system.

Makes sense.

Fafnir actually makes both real bearings (I think they're a subsidiary
of Timken now) as well as skate bearings. I have some Fafnir
machinery bearings, they're good stuff. Usually the shields on the
skate bearings are colored a bright color, the ones I have are either
green or red. The equipment bearings have black shields or are
unshielded.

I doubt that Fafnir would mislabel even skate bearings. I think that I
will buy those fake "ABEC 7" skate bearings, and will try to measure
their balls' concentricity.

i

On Sun, 28 Oct 2007 04:48:20 -0000, woodworker88
wrote:



Fafnir actually makes both real bearings (I think they're a subsidiary
of Timken now) as well as skate bearings. I have some Fafnir
machinery bearings, they're good stuff. Usually the shields on the
skate bearings are colored a bright color, the ones I have are either
green or red. The equipment bearings have black shields or are
unshielded.


Dang! Aren't we allowed to have pretty bearing shields in our lathes and mills
then?


Mark Rand
RTFM

On Sat, 27 Oct 2007 12:54:12 -0700, Diamond Dave
wrote:

On Sat, 27 Oct 2007 14:40:54 -0500, Ignoramus2057
wrote:

Since I found a pair of 7209 Fafnir Abec 7 bearing amongs some of the
stuff I took home recently, I did a little research. Looks like ABEC 7
refers to a very precise grade of bearings that are usable at very
high RPM in machine tool spindles. (this one seems to be good for 22k
RPM, for example). This stuff is god awful expensive, like $300 per
such bearing at McMaster.

At the same time, if you search for ABEC 7 on eBay, you will see a
huge quantity of a buck a dozen "ABEC 7" skateboard or roller skate
bearings.

I have hard times believing that they are really made to such
specs. (or that skateboards need such precision)

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

Probably more of a lie than clever marketing. I use ABEC-7 bearings in my
Shimano Curado fishing reels and they really are slick. I get them he
http://mikesreelrepair.com/
And they aren't that cheap, but Mike sells them for less than anywhere else I've
found.
As far as I can tell, ABEC-7 bearing are supposed to have ceramic balls/rollers
and I have my doubts about how much shock they could take on a skate board
type use.

ceramic bearings are used in a locally made, internationally marketed,
model jet turbine.
I asked the guy how much shock load a ceramic bearing could take.
"Hmmm let me show you"
He had a beairng that they had cut apart using a dremel cutoff blade
and took a ball out of the bearing.
on the back peening pad on his 6" bench vise he placed the ball.
then he gave it one almighty whack with the largest size ball pein
engineers hammer. I mean he really laid into it!
on the bench vise could be seen a hemispherical dimple that looked to
be half the size of the ball. in the face of the hammer was a smaller
hemispherical divot.
the ball itself was lost down the back of the workshop because we
heard it smack the rear door.

some of those little balls can be damn near indestructable.

Stealth Pilot

On Sun, 28 Oct 2007 21:25:23 +0900, Stealth Pilot
wrote:

On Sat, 27 Oct 2007 12:54:12 -0700, Diamond Dave
wrote:

On Sat, 27 Oct 2007 14:40:54 -0500, Ignoramus2057
wrote:

snip
ceramic bearings are used in a locally made, internationally marketed,
model jet turbine.
I asked the guy how much shock load a ceramic bearing could take.
"Hmmm let me show you"
He had a beairng that they had cut apart using a dremel cutoff blade
and took a ball out of the bearing.
on the back peening pad on his 6" bench vise he placed the ball.
then he gave it one almighty whack with the largest size ball pein
engineers hammer. I mean he really laid into it!
on the bench vise could be seen a hemispherical dimple that looked to
be half the size of the ball. in the face of the hammer was a smaller
hemispherical divot.
the ball itself was lost down the back of the workshop because we
heard it smack the rear door.

some of those little balls can be damn near indestructable.

Stealth Pilot

Ouch! Why would he do that to his vise or hammer? Or potentially
either of you? That certainly demonstrated his point, but you have to
wonder about his thought processes. I bet he's done the same trick
before.

Pete Keillor

On Sat, 27 Oct 2007 12:54:12 -0700, Diamond Dave
wrote:

On Sat, 27 Oct 2007 14:40:54 -0500, Ignoramus2057
wrote:

Since I found a pair of 7209 Fafnir Abec 7 bearing amongs some of the
stuff I took home recently, I did a little research. Looks like ABEC 7
refers to a very precise grade of bearings that are usable at very
high RPM in machine tool spindles. (this one seems to be good for 22k
RPM, for example). This stuff is god awful expensive, like $300 per
such bearing at McMaster.

At the same time, if you search for ABEC 7 on eBay, you will see a
huge quantity of a buck a dozen "ABEC 7" skateboard or roller skate
bearings.

I have hard times believing that they are really made to such
specs. (or that skateboards need such precision)

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

Probably more of a lie than clever marketing. I use ABEC-7 bearings in my
Shimano Curado fishing reels and they really are slick. I get them he
http://mikesreelrepair.com/

Hey, these look good for a project I have in mind. Do they have lower
low-speed starting and rolling resistance than lesser bearings? The
project is a little cup-type aenomometer. I got the hemispherical
cups last week.

On Oct 28, 1:45 am, Wes wrote:

I was at a Favnir or SKF class a few years ago. They said they didn't make
an ABEC 1 and a 3 was likely to be a 5 since their goal is to make good
bearings.

Wes

RIght. My understanding is that they try to make the best bearings
that they can. Then test them and sort them into the various grades.
If they managed to make mostly bearings that meet ABEC-5, they sell
all they can as ABEC-5, and the rest are sold as ABEC-3.

Dan

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

There is a company selling skateboard bearings that is named "ABEC-7"
and it has nothing to do with their quality. You are correct that a
true ABEC -7 bearing meets extremely tight tolerances.

As far as I can tell, ABEC-7 bearing are supposed to have ceramic balls/rollers
and I have my doubts about how much shock they could take on a skate board
type use.
Not necessarily. Most ABEC-7 bearings are all steel - ceramic is a
totally different animal for different purposes - primarily heat and
electrical isolation.

Hey, these look good for a project I have in mind. Do they have lower
low-speed starting and rolling resistance than lesser bearings? The
project is a little cup-type aenomometer. I got the hemispherical
cups last week.
You may get just the opposite effect. Because the tolerances are held
so closely you may have less internal clearance (unless you specify
more). Best bet is to consider the lubricant and use a minimal amount
of very lightweight oil.

On Sun, 28 Oct 2007 04:48:20 -0000, woodworker88
wrote:

On Oct 27, 12:40 pm, Ignoramus2057
wrote:

I had a long discussion with a particularly stubborn friend of mine
about this very topic.

ABEC 7 is the grade used for machine spindle bearings, and is
obscenely expensive (when the tolerances are held to +/- 0.0001",
you'd kinda expect it to be). Nearly all ABEC 7 bearings I've ever
encountered were tapered roller bearings.

Most of the ABEC - 7's will be Angular Contact Ball Bearings or Single
Row Deep Groove Ball Bearings.

The skateboard manufacturers just use it as a cool name, most skate
bearings are ABEC 3 at best. Most non-engineers aren't aware of the
real system.

Fafnir actually makes both real bearings (I think they're a subsidiary
of Timken now) as well as skate bearings. I have some Fafnir
machinery bearings, they're good stuff. Usually the shields on the
skate bearings are colored a bright color, the ones I have are either
green or red. The equipment bearings have black shields or are
unshielded.

Shields are usually left in their natural metallic color whereas seals
are colored with the colors denoting the material.

On 2007-10-29, (Tom) tom wrote:

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

There is a company selling skateboard bearings that is named "ABEC-7"
and it has nothing to do with their quality. You are correct that a
true ABEC -7 bearing meets extremely tight tolerances.

Maybe I should open a company called "18k Gold" and start making crap
jewelry...

i

I doubt that Fafnir would mislabel even skate bearings. I think that I
will buy those fake "ABEC 7" skate bearings, and will try to measure
their balls' concentricity.

i
None of the major manufacturers will mislabel any bearings and in fact
strive to make everything as close to the middle of the tolerance
range as possible which is why bearings sold as ABEC-1 will usually
meet ABEC-3 standards (from the majors). DuPont did a comparative
study between the largest bearing manufacturers in the world and
checked manufacturing processes, quality control procedures,
metallurgy etc. and ranked them accordingly. NTN was determined to
make the highest quality bearing followed by NSK, FAG and SKF in that
order. Fafnir wasn't large enough at the time to be considered but
they do make a fine bearing (as do all of the above). All make high
quality bearings that meet or exceed the standards but there was a
slight variation in the adherence to the center of the tolerance
range, concentricity etc. This is not necessarily true of some of the
"off brands".

On 2007-10-29, (Tom) tom wrote:

I doubt that Fafnir would mislabel even skate bearings. I think that I
will buy those fake "ABEC 7" skate bearings, and will try to measure
their balls' concentricity.

i
None of the major manufacturers will mislabel any bearings and in fact
strive to make everything as close to the middle of the tolerance
range as possible which is why bearings sold as ABEC-1 will usually
meet ABEC-3 standards (from the majors). DuPont did a comparative
study between the largest bearing manufacturers in the world and
checked manufacturing processes, quality control procedures,
metallurgy etc. and ranked them accordingly. NTN was determined to
make the highest quality bearing followed by NSK, FAG and SKF in that
order. Fafnir wasn't large enough at the time to be considered but
they do make a fine bearing (as do all of the above). All make high
quality bearings that meet or exceed the standards but there was a
slight variation in the adherence to the center of the tolerance
range, concentricity etc. This is not necessarily true of some of the
"off brands".

I spent approximately $7 and will soon receive those "abec 7" skate
bearings. I will then try to measure concentricity of their balls when
I receive them in a few days.

i

"Ignoramus32225" wrote in message
...
On 2007-10-29, (Tom) tom wrote:

I doubt that Fafnir would mislabel even skate bearings. I think that I
will buy those fake "ABEC 7" skate bearings, and will try to measure
their balls' concentricity.

i
None of the major manufacturers will mislabel any bearings and in fact
strive to make everything as close to the middle of the tolerance
range as possible which is why bearings sold as ABEC-1 will usually
meet ABEC-3 standards (from the majors). DuPont did a comparative
study between the largest bearing manufacturers in the world and
checked manufacturing processes, quality control procedures,
metallurgy etc. and ranked them accordingly. NTN was determined to
make the highest quality bearing followed by NSK, FAG and SKF in that
order. Fafnir wasn't large enough at the time to be considered but
they do make a fine bearing (as do all of the above). All make high
quality bearings that meet or exceed the standards but there was a
slight variation in the adherence to the center of the tolerance
range, concentricity etc. This is not necessarily true of some of the
"off brands".

I spent approximately $7 and will soon receive those "abec 7" skate
bearings. I will then try to measure concentricity of their balls when
I receive them in a few days.

To be fussy about it, you're more likely to measure roundness than
concentricity, and more likely to measure deviation of diameter than
roundness, which is not exactly the same thing.

[Sorry about that, but I wrote an article about it once. d8-)]

--
Ed Huntress

Ignoramus32225 wrote:

Maybe I should open a company called "18k Gold" and start making crap
jewelry...


You are worrying me.

On Mon, 29 Oct 2007 01:02:04 GMT,
(Tom) wrote:


Hey, these look good for a project I have in mind. Do they have lower
low-speed starting and rolling resistance than lesser bearings? The
project is a little cup-type aenomometer. I got the hemispherical
cups last week.
You may get just the opposite effect. Because the tolerances are held
so closely you may have less internal clearance (unless you specify
more). Best bet is to consider the lubricant and use a minimal amount
of very lightweight oil.

I wondered about that. Seems like the precision bearings in my
toolpost grinder, probably ABEC-7, are rather stiff.

Speed and load will be low in an anenomometer, so precision really
isn't necessary. I'll probably use small motor bearings or router
guide bearings.

On Sun, 28 Oct 2007 20:15:27 -0500, Ignoramus32225
wrote:

On 2007-10-29, (Tom) tom wrote:

Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

There is a company selling skateboard bearings that is named "ABEC-7"
and it has nothing to do with their quality. You are correct that a
true ABEC -7 bearing meets extremely tight tolerances.

Maybe I should open a company called "18k Gold" and start making crap
jewelry...

i

In the 50's, when "made in Japan" was worse than "made in China" is
today, there was a town named "Usa" in Japan so they could mark stuff
"made in usa". Or so it was reported in the Reader's Digest.

On Mon, 29 Oct 2007 01:02:04 GMT,
(Tom) wrote:


Hey, these look good for a project I have in mind. Do they have lower
low-speed starting and rolling resistance than lesser bearings? The
project is a little cup-type aenomometer. I got the hemispherical
cups last week.
You may get just the opposite effect. Because the tolerances are held
so closely you may have less internal clearance (unless you specify
more). Best bet is to consider the lubricant and use a minimal amount
of very lightweight oil.

The internal clearance on deep groove bearings is specified
independently of the the precision class. As far as I know, the
standard clearance is more or less the same across all classes.

Lubricant _is_ a very big factor if the goal is to minimize friction
at low loads. I kludged a simple test rig to measure bearing drag for
a project that required very low drag at high speeds. It consisted of
a piece of fine spring wire held in the Bridgeport spindle which drove
the outer race of the bearing. A strobe illuminated a circular paper
scale graduated to indicate the deflection of the spring with the
spindle turning. It was easy to see the effect of lubicant viscosity
with this setup.

I thought I had a photo, but all I can find is the final product.
http://www.suscom-maine.net/~nsimmons/news/P8260002.JPG
http://www.suscom-maine.net/~nsimmons/news/P8260001.JPG

The geometry of deep groove bearings guarantees there'll always be
some sliding between the balls and race, so they're not ideal where
friction must be minimized.

--
Ned Simmons

On Sun, 28 Oct 2007 04:48:20 -0000, woodworker88
wrote:

Nearly all ABEC 7 bearings I've ever
encountered were tapered roller bearings.

ABEC classes never apply to tapered roller bearings - they use an
entirely different system.

--
Ned Simmons

Don Foreman wrote:

Hey, these look good for a project I have in mind. Do they have lower
low-speed starting and rolling resistance than lesser bearings? The
project is a little cup-type aenomometer. I got the hemispherical
cups last week.

Do real anemometers have ball bearings? I'm thinking my cheapy weather
station has bushings.

Wes

Ignoramus2057 wrote:
Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

100% marketing. So silly, there is a wheel mfg. called ABEC 11.

I use this guys bearings:
http://www.skatetechnology.com/rocknronsbearings.htm

Ceramics are the way to go. A buddy of mine gets them direct, so I pay $45
for the ceramics. They are 608's. I tried the Enco steel equivalent, but
they pack them with grease instead of light oil. Drags something fierce in
the bowl.

When my wheels are still spinning after popping out of the pool 3 minutes
later, groms always come up and ask the ABEC rating of my bearings. Silly
kids.

Check me out:
http://phocksden.net/forum/images/av...2d160ef469.gif
--
John L. Weatherly

please remove XXXs to reply via email

On Oct 29, 2:41 am, Don Foreman wrote:


Speed and load will be low in an anenomometer, so precision really
isn't necessary. I'll probably use small motor bearings or router
guide bearings.

I would use Teflon or jewel bearings. I think that any ball bearings
would have more low speed drag especially if they have seals. A
stainless shaft and either a glass jewel or teflon would not need
protection from the elements.

Dan

On Sat, 27 Oct 2007 21:45:58 -0400, Wes wrote:

Ignoramus2057 wrote:

At the same time, if you search for ABEC 7 on eBay, you will see a
huge quantity of a buck a dozen "ABEC 7" skateboard or roller skate
bearings.

I have hard times believing that they are really made to such
specs. (or that skateboards need such precision)


I was at a Favnir or SKF class a few years ago. They said they didn't make
an ABEC 1 and a 3 was likely to be a 5 since their goal is to make good
bearings.


Wes

When were the ABEC spec's first published? I would guess today just
about any new machine used to make ball bearing is 1000X better than
is was back then. A manufacturer would have to screw up bad to make
an ABEC 1 today, IMHO.

Thank You,
Randy

Remove 333 from email address to reply.

When were the ABEC spec's first published? I would guess today just
about any new machine used to make ball bearing is 1000X better than
is was back then. A manufacturer would have to screw up bad to make
an ABEC 1 today, IMHO.

Thank You,
Randy

Not really - up through a 50 mm bore there is only 1 to 2 micron
difference in the allowable bore tolerance between each grade. For
example, a 50 mm bore ABEC -1 has a tolerance range of 0 to -12
microns whereas an ABEC-3 is 0 to -10 and an ABEC -5 is 0 to -8. If a
manufacturer allows their tolerances to float across the range there
is little difference between the ABEC grades. Since most try to stay
in the middle of the range then drifting off 4 - 5 mm would be
substantial though.

On Mon, 29 Oct 2007 08:15:06 -0600, "John L. Weatherly"
wrote:

Ignoramus2057 wrote:
Are those skateboard bearings really made to ABEC 7? Or is that some
clever marketing ploy?

100% marketing. So silly, there is a wheel mfg. called ABEC 11.

I use this guys bearings:
http://www.skatetechnology.com/rocknronsbearings.htm

Ceramics are the way to go. A buddy of mine gets them direct, so I pay $45
for the ceramics. They are 608's. I tried the Enco steel equivalent, but
they pack them with grease instead of light oil. Drags something fierce in
the bowl.

When my wheels are still spinning after popping out of the pool 3 minutes
later, groms always come up and ask the ABEC rating of my bearings. Silly
kids.

Check me out:
http://phocksden.net/forum/images/av...2d160ef469.giF

how about a link we don't need to log into.

Thank You,
Randy

Remove 333 from email address to reply.

On Oct 27, 10:07 pm, Ignoramus2057
wrote:
On 2007-10-28, woodworker88 wrote:

On Oct 27, 12:40 pm, Ignoramus2057
wrote:

I had a long discussion with a particularly stubborn friend of mine
about this very topic.

ABEC 7 is the grade used for machine spindle bearings, and is
obscenely expensive (when the tolerances are held to +/- 0.0001",
you'd kinda expect it to be). Nearly all ABEC 7 bearings I've ever
encountered were tapered roller bearings.

The one I have, is a ball bearing. (a pair actually).
That makes sense. Most high-precision bearings are paired, such as
for the top and bottom of a machine tool spindle.

The skateboard manufacturers just use it as a cool name, most skate
bearings are ABEC 3 at best. Most non-engineers aren't aware of the
real system.

Makes sense.

Fafnir actually makes both real bearings (I think they're a subsidiary
of Timken now) as well as skate bearings. I have some Fafnir
machinery bearings, they're good stuff. Usually the shields on the
skate bearings are colored a bright color, the ones I have are either
green or red. The equipment bearings have black shields or are
unshielded.

Right, seals are colored (they're rubber) Shields are metal, and
aren't colored. I always get them confused...

I doubt that Fafnir would mislabel even skate bearings. I think that I
will buy those fake "ABEC 7" skate bearings, and will try to measure
their balls' concentricity.

i

Randy wrote:

Check me out:
http://phocksden.net/forum/images/av...2d160ef469.giF

how about a link we don't need to log into.

Oops! Sorry. Try these:

http://www.pbase.com/dimages/franklin_2006_10_15
http://home.comcast.net/~johnnytorch/root/jtrr.gif

--
John L. Weatherly

please remove XXXs to reply via email