Angular contact bearings 7201-2RS

[Michael HornerParticipant @michaelhorner54327]

Hi

I have just bought 2 Angular contact bearings 7201-2RS

I can't seem to find any information on which face is the thrust face.

I intend to use them as a pair so it is important they go the right way round.

This variant has two rubber seals which I don't want to damage which makes a visual examination difficult.

From the scant information I have found I think the side with the bearing identification on is the thrust face. So when I mount them in the spindle housing the the identificatons should face each other.

Can anybody confirm theis?

TIA

Cheers Michael.

[Michael HornerParticipant @michaelhorner54327]

Which side is the thrust side.

[AjohnwParticipant @ajohnw51620]

No but the outer ring is usually thicker on the side that takes thrust.

John

–

[Bob Brown 1Participant @bobbrown1]

Should be easy to work it out as the ends will have a thick and thin face

Bob

[Michael HornerParticipant @michaelhorner54327]

Thank you for the prompt replies guys and the optimism!

The bearing on the left has the bearing id. (front, thrust side?) the right bearing is the rear view

To my eyes apart from the bearing id they look the same. I don't want to disturb the seals because they will be working in a dusty enviroment.

The od is 32mm.

Cheers Michael.

[Michael GilliganParticipant @michaelgilligan61133]

Michael,

Having seen the picture, I certainly understand your confusion !!

Bob's diagrams look so clear, but your photo shows the reality.

Common Sense would suggest that the markings should be on the outside face, so that they remain visible when installed … but, sadly, we can't rely upon Common Sense.

MichaelG.

[Douglas JohnstonParticipant @douglasjohnston98463]

Are you really sure they are angular contact bearings since they look just like ordinary ball bearings. Any true angular contact bearings I have seen can be identified by the thick/thin ends as shown above, but then again I have not seen that many.

Doug

[V8EngParticipant @v8eng]

Have you tried asking the supplier for this advice?

Edited By V8Eng on 17/06/2015 20:13:25

[Douglas JohnstonParticipant @douglasjohnston98463]

Second thought, it probably is the rubber shield that has hidden the thicker side, making both sides look the same, but that does not solve your problem!

Doug

[Bob Brown 1Participant @bobbrown1]

I would be inclined to pop one of the seals off to look at the internals.

[Michael HornerParticipant @michaelhorner54327]

Hi

DJ. 7201 is the code for a single row angular contact bearing. The contact angle is only 15 degrees which might explain why it doesn't have dissimilar sizes. I have had a spanner recently marked up as 8mm when it was a 7mm.

I believe the country of origin is U.A.E The invoice states they are angular contact.

V8. Rang them at 16:30. He said he would have to ring technical!

I was hoping Ketan had his ears on, he sells these but was out of stock. He supplied the middle bit which fits very well.

**LINK**

The above links to a pdf. The picture of the bearing has the id to the front and if I understand angular contact bearings, that is the thurst side.

So in my application Michael G the writing will be on the inside because the spindle will be appling the pre-load.

Thanks for your replies.

Ketan is probably looking for the £3 he owes JS

Cheers Michael.

[Neil WyattModerator @neilwyatt]

The inner ring on the right hand bearing looks thicker to me. As the asymmetry applies to the inner ring as well…

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Horner on 17/06/2015 20:39:46:

… in my application Michael G the writing will be on the inside because the spindle will be appling the pre-load.

.

Fair enough, Michael

I'm intrigued … Do you have a picture ?

MichaelG.

[Michael HornerParticipant @michaelhorner54327]

Posted by Neil Wyatt on 17/06/2015 20:51:01:

The inner ring on the right hand bearing looks thicker to me. As the asymmetry applies to the inner ring as well…

Neil

Hi Neil

Tried to measure with a digital caliper, result was inconclusive because of the curve on the inner edge.

Also tried to measure the displacement of the centre bit, again inconclusive. Not good on fiddily things.

Cheers Michael

[Michael HornerParticipant @michaelhorner54327]

Posted by Michael Gilligan on 17/06/2015 20:55:11:

Posted by Michael Horner on 17/06/2015 20:39:46:

… in my application Michael G the writing will be on the inside because the spindle will be appling the pre-load.

.

Fair enough, Michael

I'm intrigued … Do you have a picture ?

MichaelG.

Hi Michael

It is an embryonic toolpost spindle. I think the milling cutter will need to be reduced in length.

If it works I might try it as a milling spindle for engraving type work. The bearings are rated to 20000 rpm.

Cheers Michael

[Ketan SwaliParticipant @ketanswali79440]

Hi Michael,

Left work early today.

What was said earlier by John W1 and Bob makes sense.

I will check our stock in the morning and let you know. Our stock came in day before yesterday.

They don't really make any bearings in the U.A.E….just some very powerful people with influence doing paperwork for tax reasons. They are mostly made in China and a certain extent from India. Do you have any pictures with markings on the bearings and/or packaging?

Ketan at ARC.

[Michael GilliganParticipant @michaelgilligan61133]

Michael,

Thanks for the photo

Hope it goes well

MichaelG.

[Michael CheckleyParticipant @michaelcheckley34085]

Simplybearings has the dimensions on their website:

**LINK**

As Neil says the dimensions on the inner race are different so you might be able to work it out from this.

Mike

[Michael HornerParticipant @michaelhorner54327]

Posted by Ketan Swali on 17/06/2015 21:27:06:

Hi Michael,

Left work early today.

What was said earlier by John W1 and Bob makes sense.

I will check our stock in the morning and let you know. Our stock came in day before yesterday.

They don't really make any bearings in the U.A.E….just some very powerful people with influence doing paperwork for tax reasons. They are mostly made in China and a certain extent from India. Do you have any pictures with markings on the bearings and/or packaging?

Ketan at ARC.

Hi Ketan

Best I could do.

Cheers Michael.

[Michael HornerParticipant @michaelhorner54327]

Posted by Michael Checkley on 17/06/2015 21:59:44:

Simplybearings has the dimensions on their website:

**LINK**

As Neil says the dimensions on the inner race are different so you might be able to work it out from this.

Mike

Hi Mike

That's where they came from.

Mine are the cheap as chips variety.

Just done a measurement as per the info and there is a slight differance.

Got to take the cat for a walk, I kid you not.

When I get back I will see if the measurment fit in with what I think.

Cheers Michael.

[Michael HornerParticipant @michaelhorner54327]

Hi all

I have measured what I call the id side, the side with bearing number, 7201B. It is 27.96mm. This is in effect the seal od.

The other side measures 28.39mm.

Making the id side the thicker one and the thurst side. So in my design the two id's will face each other.

Just got to make up a locking coller to trap the spring to apply a little preload, find a motor to fit then try it out!

Thanks for all your help.

Cheers Michael

[Ady1Participant @ady1]

What a fabby question

IMHO the stamped edge is the "key" to your problem

Which way round it is though….

I would pop them both off though, just to be sure, since it is a critical application

If one happens to be the wrong way round, what are you going to do? sue?

And My guess is:

The stamping is normally the weak point, so it's the outside part

Edited By Ady1 on 18/06/2015 00:47:57

[Paul BarrettParticipant @paulbarrett57424]

Below is an image of a 7201-2RS bearing. You can plainly see the diiference between the thrust and non thrust faces.

Paul

[Michael HornerParticipant @michaelhorner54327]

Posted by Paul Barrett on 18/06/2015 07:00:08:

Below is an image of a 7201-2RS bearing. You can plainly see the diiference between the thrust and non thrust faces.

Paul

Wow!

Thankyou for that Paul. You wouldn't happen to know what the contact angle is?

Just gone back and checked the link from Mike C and there is no mention of contact angle.

From your picture Paul, the ID side is the thurst side.

I will have to see what Simply Bearings come back with.

Cheers Michael.

[Paul BarrettParticipant @paulbarrett57424]

Michael.

As far as I am aware they are 15 degree which I believe is most common and supplied without question. 25 degree is only supplied on request.

I run the bearings back to back (idents facing each other) but because they are not a matched pair I use shims between the outers to obtain the correct loading. I use these on my cnc router for the ballscrews to take the thrust loads on all the axis's.

Hope that helps.

Paul.

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