×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Stainless Steel Tapered Roller Bearings

Stainless Steel Tapered Roller Bearings

Stainless Steel Tapered Roller Bearings

(OP)
We use tons of tapered roller bearings, but our supplier does not manufacture stainless steel ones.

We can get stainless steel ball bearings - good quality, no problems.

I would like to try some stainless steel tapered roller bearings (SSTRBs).  But I don't have time or money to waste on poor quality.  

Do any of you currently use SSTRBs and if so, who makes them?

RE: Stainless Steel Tapered Roller Bearings

What are your parameters, app., environment, dimensions,
send diagram for load appreciation. There are many outlets for bearings, and 'STAINLESS' is really an ambiguous description; where case-hardened is the ploy for tapered-roller bearings (RC 56-64), stainless must see lighter load
but is 'more forgiving' of contaminants (nicks & scratches showing)instead of shattering.

                           thestocksguy@hotmail.com

RE: Stainless Steel Tapered Roller Bearings

(OP)
I agree Stainless is ambiguous, but it is meant to be because the parameters vary so much from application to application.

When Stainless Steel TRBs are requested, they always go into a product that has stainless steel components.

Currently we provide the stainless steel components, which by the way have load ratings far below our normal hardened steel, and apply special coatings to the TRBs so we "might" get the effect of stainless steel.

We still get requests for entirely stainless steel products - and we're stumped because we don't currently have a stainless steel TRB supplier.

To summarize:  I am looking for a supplier that has been in business for ... say 25 years or more, whose name is known for its quality products, and who has reputation for being the best at what they do.

Bearing bore sizes of interest vary from .75" thru 5".

Thanks for your help.  

RE: Stainless Steel Tapered Roller Bearings

(OP)
I expect the BDRs and static load ratings to be lower than for steel TRBs.  I just want to find a quality bearing made by a quality manufacturer.

RE: Stainless Steel Tapered Roller Bearings

Check out Timken Roller Bearing Company
in Canton, Ohio.  They probably have a web
site.  

RE: Stainless Steel Tapered Roller Bearings

(OP)
All our TRBs are from Timken - tons and tons a year.  A Timken sales rep, who is originally from Italy and now based in Chicago, bought me lunch last week.  They do not make SSTRBs.  They do coat with Aquaspex which purportedly provides protection similar to SS.

They are in the process of acquiring Torrington.  This will make Timken the 3rd largest bearing manufacturer in the world.

I cannot find SSTRBs in Torrington's catalog or at their website.

Thanks for the guess, but I was hoping for personal experience.

RE: Stainless Steel Tapered Roller Bearings

Massey,
Timken did make ss tapered roller bearings
and they had a ss suffix after the part numbers
to indicate ss.  I guess the market was such
that it became cost prohibitive.  I worked
there moons ago in the engineering department.
Sorry if I threw you a curve.

RE: Stainless Steel Tapered Roller Bearings

(OP)
No problem.  Thanks for the info. - I wasn't aware of that.

RE: Stainless Steel Tapered Roller Bearings

Just curious if you were able to find a SS bearing supplier?

I am currently looking for SS tapered roller bearings or thrust bearings myself, with little or no luck.

We have specific underwater applications that require the use of stainless steels.

RE: Stainless Steel Tapered Roller Bearings

(OP)
drclark,

No luck yet, we continue to use AquaSpexx coated bearings from Timken.  They are coated for applications such as you mentioned.  In fact they make bearing replacement kits designed specially for boat trailors or other very wet enviroments.

I found one supplier in China that will supply chromed tapered roller bearings, I have not obtained a sample and do not think I will persue one at this time.

If you do locate Stainless Steel Tapered Roller Bearings, please let me know.

Thanks.

RE: Stainless Steel Tapered Roller Bearings

I'm also on the lookout for a ss trb supplier. I've yet to  find one.

I'm about to get a sample of the Aquaspexx you mentioned. Do they perform well? I shall be fitting them to boat trailers, which go in and out of salt water regularly (lifeboats and beach rescue).

I hear Timken did make SS bearings but as dimondjim says, but they weren't cost effective for the negligible improvement in performance.

I'd appreciate any advice,

Cheers,

RE: Stainless Steel Tapered Roller Bearings

Massey and others,
  Good luck in your search for TRB's in stainless.  I made the same search last year.  99.9% of the worlds bearings are made from 52100C steel which rusts rapidly without some coating protection.  Most coatings offered wear off after some time in service due to high contact stresses.

  440C is the "stainless" material in most of the smaller ball bearings and works well, requiring no coating and offering good corrosion resistance and life.  But, it is apparently not a usable material in the larger sizes and in the TRB's.

  FAG/Barden/Germany offers a proprietary process called "Cronidur" which they claim has the corrosion resistance, life, and performance of 440C.  They make this process available for the larger sizes of bearings including roller bearings.  These units are expensive relative to the 52100C counterparts.

RE: Stainless Steel Tapered Roller Bearings

If your application is boat trailers, try changing the grease to something like an overbased calcium sulphonate (TOTAL FINA CERAN HV or similar). This does not emulsify easily with water (like normal greases do) and I have used this with great success launching ski-boats into the sea off Durban.

Stainless generally too soft to make bearings, it's expensive and difficult to work. However, there are specialists who will make ball, and cylindrical roller bearings in stainless (generally small, private workshops - not the 'big guys'), but not tapered rollers.

Have you got a definite requirement?

Lester Milton
NBC Group Ltd, Telford, Shropshire, UK

RE: Stainless Steel Tapered Roller Bearings

Cheers Lester,

I've got my hands on some samples of grease which I'll be putting on trial shortly. Not sure what these comprise of but are supposedly tailored for aquatic environments.

I think one is by Fuchs and called Renolit Aqua 2 or XL or something. The other is by Rocol and called Sapphire Aqua 2.

I'll post details of how well they performed.

Andy
RNLI, Poole, UK

RE: Stainless Steel Tapered Roller Bearings

I know them both - if you want some of the other for testing let me know. We are on the internet!

Lester Milton
NBC Group Ltd, Telford, Shropshire, UK

RE: Stainless Steel Tapered Roller Bearings

(OP)
Timken's AquaSpexx coating was originally designed for boat trailors as a bearing replacement 'package'.

We've used some AquaSpexx coated bearings that are supplementally treated with MicroPoly or CobraLube.  The solid lubricants do not break down under water.  They can be used in submerged conditions and CobraLube has the added benefit of temps. up to 500F.

I am still looking for Stainless Steel TRBs although not as ardently as before because I have come to believe that they do not exist.



RE: Stainless Steel Tapered Roller Bearings

Massey,

I think you have an interesting problem, and in fact, I once had a boat trailer with heavy corrosion on the roller bearings of the wheels. Here is one solution:instead of installing stainless steel bearings to resist the leakage inward of corrosive water, why don't you use standard roller bearings, and modify the bearing housing so that simple mechanical face seals are used to seal out the water.You will only need one seal per bearing, if designed properly.

The seals can be low cost off-the-shelf that are normally applied to centrifugal pumps. In addition, I would imagine that your boat trailers are using automotive parts for the bearing holder. I would advise modifying these if possible, to accept externally mounted simple carbon face mechanical seals. Of course, the grease will still be packed inside this chamber, however, now, the water will not be able to leak in. In addition, on the road, the resulting dry friction of the seal faces is negligible due to the face velocities.



abdul

RE: Stainless Steel Tapered Roller Bearings

(OP)
Thanks abdul,

We got talking about boat trailors cuz of AquaSpexx and like coatings, and someone posted a question about boat trailor application somewhere above.  However, I am searching for SS TRBs to put in SS products that the company I work for produces and markets.

I do have a couple boat trailors but they are not exposed to salt water and I just use the spring loaded dust covers with a grease fittings installed.  I just add grease when they need it and don't worry about them.

My search for SS TRBs has nothing to do with boat trailors.

But your idea is a good one and one I would try if I had a problem with boat trailors.

Thank you,

RE: Stainless Steel Tapered Roller Bearings

Massey

Does your bearing have to be a tapered roller? Ball bearings are commonly available, and there are also the mounted ball bearing units in thermoplastic housings?

Would either of these suit your needs?

We are currently manufacturing some special cam followers in stainless for a sugar mill application, but they are horribly expensive! We could probably look at making some cylindrical roller bearings in stainless, but i would shy away from tapered rollers bearings.

Lester Milton
NBC Group Ltd, Telford, Shropshire, UK

RE: Stainless Steel Tapered Roller Bearings

Just a quick update on my problem. I've taken to the idea of finding a suitable seal for the hubs, rather than look for a corrosion resistant bearing.

Any bearing given time will corrode if (in my case) salt water enters the wheel hub. So I plan to prevent that from happening. Have found a couple of manufcaturers (John Crane - ProTech Bearing Isolators and SKF).

We make our own phosphor-bronze bearings for launch trailers as they aren't towed on the road. But for road going trailers this would be illegal, so we use the standard trb's. Depending on the application, ball bearings might work just as well (providing the thrust loads aren't prohibitively high).

I also looked at plastic bearings from WYKO, but these were ruled out as the shock loads from towing the trailers over rough ground would simply destroy them. But they might suit other applications.

SKF manufacture stainless ball bearings units. Might help!

Andy Covington
RNLI

RE: Stainless Steel Tapered Roller Bearings

(OP)
HIPPO41,

We stock and use SS ball bearings.  I need SS TRBs because the BDR and Static load ratings are much higher for relative size as compared to BB.

The draw back with Cylindrical Roller Bearings is the abscence of thrust [axial] load handling capability.

Thanks for the input.

RE: Stainless Steel Tapered Roller Bearings

(OP)
CovyUK,

I just got finished reading up on the new ICOS oil seal from SKF and CR.  It might work well for your application.  They are available in the 6000 series BB in sizes from 12mm to 40mm.
The concept takes a traditional Chicago Rawhide spring lip shaft oil seal and mounts it on the bearing unit directly.


RE: Stainless Steel Tapered Roller Bearings

MASSEY,

Any chance you could combine a cylindrical roller and a ball thrust bearing to accomplish what you need to do?

Mike

RE: Stainless Steel Tapered Roller Bearings

Massey,
Is there any specific reason why you have to avoid sealings?
Is "use SSTRB"  a designer's specification?

Since your application calls for a tappered roller bearing, your load is not so light. I would prefer to use a lip seal, with some kind of laberinth, and the whole roller cavity filled with grease that would escape/fill the laberinth when the roller is lubbed, taking out any grease that might have emulsified.

sancat  

RE: Stainless Steel Tapered Roller Bearings

(OP)
Strokersix, I don't think the incorporation a thrust bearing is practical for two reasons: first is space limitations and the second is cost.  These brgs are used for a manufactured line of products of which we produce tens of thousands per year, we search for savings in fractions of pennies per product.  Another problem with a thrust brg is how the load would be transferred to it.  With the BBs and TRBs the axial component of thrust loading is applied through a retaining ring for the BBs and the cup spacer for TRBs.

Sancat, we use sealings now, fortunatly SSTRB is not a designer spec.  You see, we offer standard products and stainless steel products.  The SS products that use BB are all SS.  But the SS products using TRBs are all SS except for the Brgs.  I was just searching for SSTRBs so the entire product could be advertised and sold as SS.  This would be an appealing selling point for food handling industries.

RE: Stainless Steel Tapered Roller Bearings

Massey,

Interesting replies from everyone....I like difficult problems like this, it takes the cobwebs off of my brain.

Here is one more solution: Use radial stainless steel ball bearings, in addition to a single stainless steel ball-thrust bearing, which is placed at the shaft shoulder, just outboard of the radial bearing (which is on the major diameter).

The ball thrust bearings are practical if your shaft surface velocities are not excessive. I don't know if you are familiar with these, they have the balls rotating on a race which is oriented axially with respect to the shaft.


One more solution: Maybe you can find Silicon Nitride bearings in tapered roller bearing format, running in a stainless steel race. There are also other types of ceramic rolling element bearings, but prices may become prohibitive. However, I have seen a lot of purchasers fork over a  lot of money just to satisfy a small detail in the purchase specification.   

Naturally, the ceramic roller bearings are just as corrosion resistant as stainless steels. They are normally used in high temperature applications.

Abdul

RE: Stainless Steel Tapered Roller Bearings

what is the applicaton where SS would be necessary.  If it is say saltwater corrosion, then you need to use a duplex stainless steel for starters, not just any stainless.  Second, have you looked into coatings for the bearings, such as Xylan, ceramkote, or even plating.  I see by your earlier statements that cost is a factor so I would guess that Inconel, Monel, Hastoloy or something like that is our of the question

RE: Stainless Steel Tapered Roller Bearings

(OP)
abdul, the SS BBs have sufficient thrust capacity relative to radial capacity.  So combining a dedicated thrust brg with standard single row deep grooves seems unecessary.  The problem comes with higher radial load ratings where TRBs are required.  Their thrust capacity is also relative and sufficient.  The other suggestions would also 'work' but are not appealing due to cost.

Russian1, you hit the important point in that the TRBs are not "necessary" which is good in that they are not available.  The reason I was trying to locate them as stated above in various places is that when customers request a SS product it would be 'nice' to provide them with a SS product - not a product that has SS components with non-SS brgs.

Typical requests are in sterilzers, wash-down environments, food processing lines, or corrosive environments.  We do use coatings on the TRBs we put in SS products.  This seems to be the only solution available at the time.

I'm perplexed that SSTRBs are not available, especially since SSBBs are available.

I appreciate everyones' comments and input.

RE: Stainless Steel Tapered Roller Bearings

Massey,

 If the shaft rpm does not exceed 500 rpm, then why not use graphite sleeve bearings, with captured grease lubrication, such as using O-rings rubbing lightly on the shaft.


 

RE: Stainless Steel Tapered Roller Bearings

Have you looked into angular contact ball bearings such as those used in spindle bearings? These can take an appreciable  amount of side load while maintaining the advantages of ball bearings.

RE: Stainless Steel Tapered Roller Bearings

Stainless steels are difficult to get the
required surface hardnesses and the capactities
fall off quickly.  I do see straight stainless
steel rollers being incorporated in wire race
designs.  If they can make stainless steel
rollers, I assume the tapered races could be
made if the quantities were sufficient.  The wires
that they roll on are about 51Rc and hardened
and passivated.  I am not certain about the hardness
of the rollers but I would guess about 55Rc.
AFBMA lists stainless steel as a material suitable
for rollers.  I do not know the hardening technique
required to harden the races of a tapered raceway.
The cup should be easy but the cone would be very
difficult.  I do not know if stainless steel requires
any special grease to be incorporated into the design to be compatable with the application.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources