# Router Motor Bearing Replacement



## freudman (Jan 2, 2012)

I'd be interested to know what you recommend as a good quality bearing manufacturer to use.
I want to replace the bearings in my router motor, and it seems that bearing quality makes a big difference on how the router performs. 
I've been reading an article of a bad experience with the NSK bearings fitted to the Portamate router motor https://www.horizontalroutertable.com/nsk-bearings-100-failure/


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## Stick486 (Jan 4, 2013)

Made in China bearings is just about always a crap shoot...
I prefer to stay away from them...

That article on the NSK failures...
WTB under rated bearing were used for the task at hand - out of parameters... (load and speed)...
Porter cable does this... they like skateboard bearings...

for bearings. I like:
SKF...
Timken...
Fafnir...

talk to the people/experts at companies like:
*Motion, * 
*Whisler,* 
*Kaman,*
*Canadian Bearings* ......

if you are in a commercial theater, consider ceramic bearings...


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## freudman (Jan 2, 2012)

Thanks for your reply.
Seems SKF are the way to go and they are readily available in the UK.

One thing I can't find out absolutely clearly despite asking bearing suppliers, is should I fit standard bearings or C3 bearings in a router motor. I ask that because SKF do a super energy efficient bearing, which "...can provide more than twice the service life while reducing energy use"

I only want to replace the bearings once and the 'energy efficient' bearings are only a few pennies more than their standard bearings. But they only do the C3 fitment


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## Stick486 (Jan 4, 2013)

'energy efficient' bearings; sounds like marketing got a hold of that one...
they may ''help'' out where a machine runs 24/7...

I always thought of C3 bearings as ''sloppy''... (the ''C'' standing for ''Clearance'')
too much clearance and you get runout..

your primary concern is the sustained speed rating...
a bearing rated for 17/18K no load RPM in a 25KRPM machine is doomed to fail sooner than later...


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## Cherryville Chuck (Sep 28, 2010)

You can buy very good bearings but those may only be rated for up to 4000 rpm so they wouldn't last in a router. Watch for the rpm the bearing is rated for.


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## freudman (Jan 2, 2012)

Cherryville Chuck said:


> You can buy very good bearings but those may only be rated for up to 4000 rpm so they wouldn't last in a router. Watch for the rpm the bearing is rated for.


Thanks for that. The SKF bearings I'm looking at have a reference speed of 41,000 r/min and a limiting speed of 21,000 r/min.

The limiting speed is explained as 'the empirically obtained value for the maximum speed at which bearings can be continuously operated without failing from seizure or generation of excessive heat'

So I reckon they should be suitable for a router motor that's used only intermittently at those speeds. Plus I can't find anything higher rated than that.


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## freudman (Jan 2, 2012)

Actually, the speed figures I quoted previously were for the larger bearing at the collet end of the router motor.

The speed figures for the smaller bearing at the brushes end are:
Reference speed: 70,000 r/min
Limiting speed: 36,000 r/min


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## freudman (Jan 2, 2012)

Stick486 said:


> 'energy efficient' bearings; sounds like marketing got a hold of that one...
> they may ''help'' out where a machine runs 24/7...
> 
> I always thought of C3 bearings as ''sloppy''... (the ''C'' standing for ''Clearance'')
> ...


SKF claim that their Energy Efficient bearings "...provide more than twice the service life while reducing energy use. Design improvements reduce frictional losses in the bearing by at least 30%..." 

The standard SKF bearing has a 'Limiting Speed' of 34,000 r/min compared to the SKF Energy Efficient, which has a Limiting Speed of 36,000 r/min

The C3 bearing concerned me too, but what is 'sloppy' to me as woodworker may be miniscule to a precision bearing manufacturer. I'd be surprised if SFK produced new bearings that were sloppy.

Thanks for your input, much appreciated.


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## dwall174 (Feb 15, 2010)

freudman said:


> The standard SKF bearing has a 'Limiting Speed' of 34,000 r/min compared to the SKF Energy Efficient, which has a Limiting Speed of 36,000 r/min


freudman
Did the above quote come from SKF?

I've been looking for a good quality bearing that will hold up in a 24,000rpm router!
The main (larger) bearing in a low-cost Chinese plunge router I'm modifying for a table set-up uses a regular 6004 bearing (20mm X 42mm X 12mm)

Doug


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## Cherryville Chuck (Sep 28, 2010)

I'm not absolutely certain but I think the 6004 is one of those common cheap bearings. You could find out by going on ebay and check their bearing sellers. The 608 is the skateboard bearing and it can be had for $8 a 10 pack which makes them $.80 each. Seems to me I saw deals on 6004 bearings too.


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## DaninVan (Jan 1, 2012)

"... but what is 'sloppy' to me as woodworker may be minuscule to a precision bearing manufacturer."
-Pete
Wait...what?! That's backwards isn't it?


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## dwall174 (Feb 15, 2010)

Cherryville Chuck said:


> I'm not absolutely certain but I think the 6004 is one of those common cheap bearings.


Yeah I've seen them in packs of 10 for under $15, So they certainly are what I would call cheap bearings.

I've looked at some made by Nachi, NSK, & Timken! But none of them are rated above 18,000rpm.

Doug


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## kp91 (Sep 10, 2004)

If you can read the code etched on the side of the bearing, put EXACTLY that in there. There are a bunch of bearing cross reference tables online, or email SKF, ***, NTN if you can't find an exact match for all the extension codes. 

like everything else in the world, bearing makers manufacture their products in different places. I can tell you firsthand that the same bearings one maker can come from all over (and trust me, it is a royal pain in the butt because US customs levies duties on bearings based on country of manufacture, not where purchased from.... so getting them cleared can be a long affair). I have rarely had any issues with the 3 companies I listed above in the smaller bearing sizes, regardless of where they are made. For larger, high HP bearings I strongly recommend Timken as well.

I would blame a lot of bearing problems more on installation issues than on manufacturing issues.


https://www.skf.com/group/products/...ve-ball-bearings/permissible-speed/index.html


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## Stick486 (Jan 4, 2013)

kp91 said:


> If you can read the code etched on the side of the bearing, put EXACTLY that in there. ues.


why would you do that???
in the case of PC bearings. IMO, they fail because they weren't/aren't up to the task...
come on now.. that's throwing good money after bad...
a bearing used in a roller skate is used in a tool...
match *SIZE/DIMENSION* and make sure it's *RATED* for the task or exceeds it...


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## dwall174 (Feb 15, 2010)

kp91 said:


> I would blame a lot of bearing problems more on installation issues than on manufacturing issues.


What, You mean the trusty hammer & a old deep-well socket method is not good! :grin:

Doug


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## freudman (Jan 2, 2012)

dwall174 said:


> freudman
> Did the above quote come from SKF?
> 
> 
> Doug


Yes information from SKF


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## freudman (Jan 2, 2012)

DaninVan said:


> "... but what is 'sloppy' to me as woodworker may be minuscule to a precision bearing manufacturer."
> -Pete
> Wait...what?! That's backwards isn't it?


Agreed, I didn't word it very well.
Anyway the new SKF bearings have no 'slop' whatsoever.


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## freudman (Jan 2, 2012)

Cherryville Chuck said:


> I'm not absolutely certain but I think the 6004 is one of those common cheap bearings. You could find out by going on ebay and check their bearing sellers. The 608 is the skateboard bearing and it can be had for $8 a 10 pack which makes them $.80 each. Seems to me I saw deals on 6004 bearings too.


The 6004 does not mean it's a cheap bearing. It simply designates its size 20 x 42 x 12mm. 
You can get cheap and nasty 6004 bearings and also very good quality 6004 bearings.
I found the best quality available to me. Now they are fitted the motor is quieter and much smoother than it was when brand new. I am well pleased.


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## DaninVan (Jan 1, 2012)

Heh...saw this on 'Dilbert' today;
https://dilbert.com/strip/2020-02-08


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## Stick486 (Jan 4, 2013)

freudman said:


> I found the best quality available to me. Now they are fitted the motor is quieter and much smoother than it was when brand new. I am well pleased.


which were???


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## kp91 (Sep 10, 2004)

Stick486 said:


> why would you do that???
> in the case of PC bearings. IMO, they fail because they weren't/aren't up to the task...
> come on now.. that's throwing good money after bad...
> a bearing used in a roller skate is used in a tool...
> match *SIZE/DIMENSION* and make sure it's *RATED* for the task or exceeds it...


If you start fidgeting with the clearances, the shield or seal types, or the lubricants you can introduce failures while trying to fix others. In most cases, the engineers probably had a reason for choosing a particular bearing. I am inclined to give them the benefit of the doubt in most cases.


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## Stick486 (Jan 4, 2013)

kp91 said:


> If you start fidgeting with the clearances, the shield or seal types, or the lubricants you can introduce failures while trying to fix others. *In most cases, the engineers probably had a reason for choosing a particular bearing.* I am inclined to give them the benefit of the doubt in most cases.


economics...
let's go w/ the low bidder 
the 6004 is available in different grades/tolerances/materials/ and is either rubber or metal sealed - no need to fidget, just don't use the same *EXACT SAME SPEC'D* bearing the manufacturer used... use the same dimensions but improve quality...
BTW, cost for the 6004 is 71¢ to 36.88$ MSRP...
bump up the OEM 6004 and go ceramic..
https://www.bearingwholesalelots.com/product-p/6004-2rs-hybrid-ceramic-204212.htm

run a search for ''6004 bearings'' and start reading...


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## kp91 (Sep 10, 2004)

I'm just saying... I have seen problems when people put bearing in that are the right size, but the suffixes are not what they were designed for. Double shields put in where a single shield was required (resulted in a catastrophic failure and endbell replacement), non-contact seals put in (caused lubricant to drop at full load) ….. all those little letters mean something different. 

From my professional experience, if it says 6004 2RZ, you are better off putting back the same kind of bearing. Pick the bearing maker you want, but put the designed type in.


https://www.skf.com/us/products/rol.../deep-groove-ball-bearings/designation-system


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## Stick486 (Jan 4, 2013)

kp91 said:


> I'm just saying... I have seen problems when people put bearing in that are the right size, but the suffixes are not what they were designed for. Double shields put in where a single shield was required (resulted in a catastrophic failure and endbell replacement), non-contact seals put in (caused lubricant to drop at full load) ….. all those little letters mean something different.
> 
> From my professional experience, if it says 6004 2RZ, you are better off putting back the same kind of bearing. Pick the bearing maker you want, but put the designed type in.
> 
> ...


that is what I said...
you say EXACT, I take EXACT to mean the same piece of crap the manufacturer used...
I say put in a better quality bearing w/ the same call numbers/letters...


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## Cherryville Chuck (Sep 28, 2010)

Exactly. The same bearing can come in different grades. I had a bearing go on a router years ago and we had a specialty bearing store in town at the time. I went there to get a replacement and the guy at the counter told me that the bearing it had wasn't meant for anywhere near the rpm that the router was turning. He said he could sell me one that far exceeded that rpm but it would cost me $300.


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## dwall174 (Feb 15, 2010)

Stick486 said:


> bump up the OEM 6004 and go ceramic..


After checking around a little I ended up finding some BOCA hybrid ceramic bearings (Stainless Steel Rings With Ceramic Balls) They're rated over the 23,000 rpm of my router, Small upper bearing is rated for 28,600rpm & the large lower bearing is rated for 38,000rpm. 

Price wise they were naturally a little more, But I got both bearings for $55 delivered.
Not too bad considering these bearings will probably out-last the router!

Doug


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## Cherryville Chuck (Sep 28, 2010)

I would think it's efficiency rating should go up too, i.e. how much output power compared to how much input power. It can be as low as 60-65% sometimes.


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## freudman (Jan 2, 2012)

dwall174 said:


> After checking around a little I ended up finding some BOCA hybrid ceramic bearings (Stainless Steel Rings With Ceramic Balls) They're rated over the 23,000 rpm of my router, Small upper bearing is rated for 28,600rpm & the large lower bearing is rated for 38,000rpm.
> 
> 
> Doug


The speeds that you have quoted, are they the 'Reference Speed' as quoted by the manufacturer or the 'Limiting Speed' as quoted by the manufacturer?

For example, one of the SKF bearings I fitted has a 'Reference Speed' of 70,000 r/min and a 'Limiting speed' of 36,000 r/min


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## dwall174 (Feb 15, 2010)

freudman said:


> The speeds that you have quoted, are they the 'Reference Speed' as quoted by the manufacturer or the 'Limiting Speed' as quoted by the manufacturer?


Their web site didn't offer any information like "Limiting Speed" or "Reference Speed" 
https://www.bocabearings.com/products/smr6004c-2ys-c3-nb2-9618
https://www.bocabearings.com/products/smr6200c-2ys-nb2-8058



freudman said:


> For example, one of the SKF bearings I fitted has a 'Reference Speed' of 70,000 r/min and a 'Limiting speed' of 36,000 r/min





Stick486 said:


> which were???


Being you didn't offer any more information on the SKF bearings you used, I did a search for SKF bearings through a 
Local Supplier Using the specs from my old bearings.

None of them had a ratting over 19,000RPM. 
I did find some with "0" clearance ratings that were ratted around 38,000RPM, But they never stated "Limiting Speed" or "Reference Speed" Price wise they were even more than the ceramic bearings I got! I also noticed that some of the higher RPM ratings were for bearings designed for oil lubrication! 



kp91 said:


> If you start fidgeting with the clearances, the shield or seal types, or the lubricants you can introduce failures while trying to fix others.


As "kp91" mentions, There's a big difference between bearing types! 
While a "Shield" bearing may appear to be "Sealed" most of them require some type of external lubrication.

Doug


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## DaninVan (Jan 1, 2012)

Great discussion; very informative!
What I'm taking away is, _buy a router from a manufacturer who uses quality components from the get-go_.
a) you likely won't need to be replacing parts
b) if you do need service it will hopefully be covered under warranty, or the manufacturer may just decide to do you a good deed and look after the problem anyway.
c) if you do need a replacement part (outside of warranty) you won't have difficulty locating that part.


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## freudman (Jan 2, 2012)

The bearing specification information is readily available on the SKF website but easier to find/read here from the people I purchased the bearings from in England https://www.bearing-king.co.uk/bear...lded-deep-groove-ball-bearing-10x26x8mm/23647

I can only say my router motor is smoother, quieter and totally vibration free since I replaced the bearings. It is definitely better than when it was brand new. The bearings only lasted a few months with limited light use in my home workshop.

I have a 1958 Dominion planer/thicknesser, which I believe still has its original bearings, and they appear to be as good as new. I'm convinced of the importance of quality bearings.


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## freudman (Jan 2, 2012)

DaninVan said:


> Great discussion; very informative!
> What I'm taking away is, _buy a router from a manufacturer who uses quality components from the get-go_.


That is good advice but how do you determine that the manufacturer actually uses quality components.

For example, my router motor is the Portamate PM-P254 and it is advertised as having "Precision NSK deep groove ball bearings"

Now it's my understanding that NSK are indeed a renowned bearing manufacturer of good quality bearings. But the bearings I removed from my router were not only knackered after just a few months use, but they actually looked and felt cheap & nasty, especially when compared side-by-side with the replacement SKF bearings.

The NSK bearings I removed had 'NSK China' stamped on them and it could well be that they are not genuine NSK bearings, but cheap knock-offs. Although surely the router motor manufacturer knows that.

What I don't get is why a manufacturer would fit low quality bearings when good quality bearings are, relatively, so inexpensive.


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## Stick486 (Jan 4, 2013)

freudman said:


> 1... how do you determine that the manufacturer actually uses quality components.
> 
> 2... it is advertised as having "Precision NSK deep groove ball bearings"
> 
> ...


1... listen to others and do your home work......
https://www.amazon.com/Portamate-PM-P254-Variable-Router-Wrenches/product-reviews/B00TBF5DSY
is the product made by or for the name on the label... 
what is the country of origin..
what is the reputation of the manufacturing country... not all operate equally..
what is the reputation of the offering company...
are you the QC department or is there one in force before your purchase???..

2... sounds like something the PR department would write...

3... back to the actual manufacturer...

4... they don't care.. they're only interested in the delivered price...

5... follow the money...


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## freudman (Jan 2, 2012)

Stick486 said:


> 1... listen to others and do your home work......


You're right of course, but sometimes it's a case of buy crap or buy nothing.

You have a wide choice in the USA but in the UK it's basically plunge routers only. I had to buy from the USA and with the additional shipping and Duty it makes it an expensive purchase. Plus any warranty is void.

I knew when I bought it that it wasn't the best, but I don't regret it. It's been interesting and I've learnt a lot. And now, I'm well pleased with it.


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## DaninVan (Jan 1, 2012)

Great that it's worked out, Pete, but goes without saying that you shouldn't have had to go through that.
Do you have Hitachi over there?


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## DaninVan (Jan 1, 2012)

Yeh, seems like plunge type are pretty much all that's easily available over there...
https://www.amazon.co.uk/hitachi-router/s?k=hitachi+router


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## Cherryville Chuck (Sep 28, 2010)

Stick486 said:


> 1... listen to others and do your home work......
> 
> 
> 3... back to the actual manufacturer...



That's not as certain as you might think. If you look at this link for the Rexon Company and scroll down you'll see pictures of people using Hitachi tools and down at the bottom you'll see that they have have "partnerships" with Hitachi and Bosch. https://www.rexonproducts.com/en/ So rather than buying a Bosch tool made in a Bosch factory you may be buying a Bosch tool made in a Rexon factory. The more research I do on who makes what leads me to believe that there are very few factories actually making tools. But you are buying what that branded seller is telling the factory to make the product out of so if they specify better components you'll get a better machine.

Backing up Dan's suggestion about trying Hitachi, I have 3 of them because I like them that much. They come with a 5 year warranty and I never had a warranty issue with any of the three. I used my M12V in my router table for several years until I got my M12V2. It is far better as a table router with above table adjustability and plugs on the end of the plunge tubes to facilitate removing the plunge springs for table use. Hitachi really designed this router to be used in a table but for some inexplicable reason they didn't advertise it as such. I think the newer VE model may have taken a step backwards from the V2. Hitachi has also recently merged with Metabo which I see as a positive move as Metabo was a higher end tool maker than Hitachi so the merger may result in even better tools than before.


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## freudman (Jan 2, 2012)

DaninVan said:


> Great that it's worked out, Pete, but goes without saying that you shouldn't have had to go through that.
> Do you have Hitachi over there?


Thanks Dan.
Yes, we have Hitachi in England but only the plunge routers I think. 
I have a Hitachi M12VC fixed base router, which I bought from the USA, but I have to use it with a transformer because of the different voltages.

I've had it for a few years and I really like it; one of the quietest routers I've used and a nice smooth soft-start.

I'd definitely buy another but I think they've rebadged to Metabo HPT M12VC, and a lot cheaper. It's the shipping and Duty that spoils it.


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## Roberthan (Jan 5, 2021)

Keeping your bearings clean and well-lubricated is critical to the overall performance and safety. To keep your bearings in top shape, lubricants prevent general wear and tear by reducing friction between surfaces. When applied regularly and sufficiently, a lubricant eliminates friction, making your bearings perform faster without obstruction. It also can repel moisture to prevent rust and corrosion and builds a barrier against dirt, grime, and other contaminants that hamper the performance of your bearings.
Choosing the right lubricant to maintain your bearings can be tricky with countless options and alternatives available for your perusal.
When buying a lubricant, it’s imperative to look at the benefits it has to offer. The type of lubricant, its viscosity, and the amount needed for efficient lubrication are of equal importance.


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## Daniel_per (Mar 21, 2021)

Stick486 said:


> 'energy efficient' bearings; sounds like marketing got a hold of that one...
> they may ''help'' out where a machine runs 24/7...
> 
> I always thought of C3 bearings as ''sloppy''... (the ''C'' standing for ''Clearance'')
> ...


Worth speaking!


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## Biagio (Mar 2, 2013)

@Roberthan, are you advocating taking the router apart periodically to lubricate the bearings? Aren't most of them sealed anyway?
What type of lubricant would you recommend for a router bearing, given the speeds?


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