Questions You Should Know about Deep Groove Ball Bearings manufacturer

• Where is the nearest distributor or field sales person?Contact customer service at 1-800-323- and they can put you in touch with the area sales representative or local distributor. Or, search for an NTN Authorized Distributor here.
• Does NTN have field engineering support?NTN does provide engineering field support to our customers. Contact your local NTN sales representative to arrange a visit.
• Load ratings seem to vary from manufacturer to manufacturer, is there a single method that can be used to compare like styles of bearings?Load ratings don't really vary from among manufacturers, the methods used to calculate load ratings is different. Some manufacturers use the ABMA standard, some use the US Industry standard, some use equivalent dynamic load calculations. In general if the internal design is the same the load ratings will be equivalent.
• What factors should be considered when choosing a bearing?All application data (loads, speeds, orientation, etc.), intended use, and environment.
• Where are specific bearing types manufactured, plant-by-plant?NTN has manufacturing plants in Asia, the Americas, and Europe that each produce a wide variety of product types. Contact NTN engineering for specific bearing inquires.
• Does NTN have any OEM programs similar to Timken?Contact the NTN Sales department.
• Are BCA parts/drawings going to be available?NTN is continuing to support the BCA product line. Individual prints can be requested through NTN engineering.
• What does the term “electric motor quality” mean?The term "electric motor quality" is freely used in describing bearings that meet a perceived "higher" level of quality than the standard ABEC-1 bearing. Contact NTN marketing for an Electric Motor Quality brochure.
• Can I mix & match cups & cones from different suppliers?No, it's not recommended. While the envelope dimensions & tolerances on those dimensions are identical, the internal designs can be different. These differences can cause issues, such as early bearing failure when the components are mixed.

• What is the “4T-” prefix used for?The “4T-” prefix designates a tapered roller bearing that is made of a special grade of case-hardened bearing steel and is interchangeable with other manufacturers taper with the same part number.
• What is the difference between LLB & LLU seals?The "LB" seal is a non-contact seal for reduced torque or higher speed requirements. The "LU" seal is contact seal for better grease contamination control, but the contact friction increases torque and lowers the limiting speed.
• What is the nomenclature for Precision Bearings (P4, P5, Tolerances)?NTN follows the ISO precision tolerance classes of P0, P6, P5, P4 and P2, which are equivalent to ABMA classes ABEC 1, ABEC 3, ABEC 5, ABEC 7 and ABEC 9, respectively.
• What is the difference between T & D1 or what is the designation for an oil hole?D1 always denotes a relube feature (any bearing). T is old nomenclature for inch dimensioned bearing units housings with a relube feature.
• What is the designation for a bronze cage on cylindrical roller bearings?Usually a G1 suffix is used to indicate a bronze or brass cage in a cylindrical roller bearing. In rare applications an L1 type cage has been used as well.
• What is the designation for a tapered bore on spherical roller bearings?A tapered bore on any NTN bearing (except tapered roller bearings) is a “K” (1 to 12 ratio) or “K30” (1 to 30 ratio) suffix.
• What does CE or C0 fit mean?NTN does not use "CE" or "C0". These are competitor terms for electric motor and normal internal clearances. Clearance does not indicate any type of fit.
• What does V1 mean at the end of the deep groove ball bearing nomenclature?For NTN "V1" stands for the first special variation on this basic part number. This suffix lettering does not indicate any specific features. A print will have to be reviewed to see the exact special features.
• What does U3A mean at the end of the deep groove ball bearing nomenclature?In a part number like ZZC3/2AU3A the "U3A" can be a packaging code or specific customer identification code. This does not affect the bearing features.
• What does LD1NR mean?LD1NR is the current suffix used on cylindrical outer ring bearing unit inserts. The "L" indicates it meets the new Japanese Industrial Specifications. The "D1" indicates it has a relube feature. The "NR" means it has a snap ring groove and snap ring on the outer diameter. This new suffix (LD1NR) will replace the older suffix D1NR on all future stock orders on this type of bearing.
• Why can’t I find part numbers UL205-100, AL205-100 or JL205-100?All of these part numbers are from the bearing component of an eccentric locking collar bearing. The locking collar for all three would have EL205-100 marked on the side. Generally speaking, NTN stocks the bearing & collar together. The part number to search for would be UEL205-100, AEL205-100 or JEL205-100. This would provide you with both the bearing & the eccentric locking collar.
• What is TMB & why can’t I find the part number?The TMB material is a special material developed for ball bearings by NTN for high load & long life applications. Part numbers that use this material have the '6' replaced by 'TMB' (i.e. becomes TMB206). Many end users commonly misread this part number as TM which is a part number you will not find. When given a part number that starts with TM8... replace it with TMB... and continue your search.
• What does the C- and CM- mean on bearing units?Both of the callouts indicate that the housing comes with cast covers. C- is for an open cover. An open cover has a hole and seal to allow the shaft to continue past the bearing unit. CM- is a closed cover, which is a solid piece that closes off the bearing unit.
• What does FG1 mean?Any part that has the FG1 suffix at the end will come with food-grade solid lube. This suffix is used on both Sentinel series & standard NTN products. NTN uses a food-grade solid lube that is NSF H1 certified for use in all food production areas. If my Sentinel part does not have FG1 at the end will it have a food grade grease? Yes, ALL Sentinel series parts come filled with a food-grade grease that is NSF H1 certified. The FG1 just designates that the bearing comes with a food-grade SOLID LUBE.
• What can I do when I cannot find a specific bearing arrangement for an angular part number (i.e. DB or DF)?Instead of using the specified arrangement, you can look at using Universal Flush Ground. The Universal Flush Ground is where the bearing is made & to be assembled in any arrangement (DB, DF or DT) & perform with no issues. The part number would begin at CDB/GNP4 and end with CGD2/GNP4 (NTN) or CVDUJ74 (SNR).

• Can you substitute an E-Type CRB for a Standard CRB?Yes, as long as you use both the inner & outer rings. When you switch to the E-Type CRB, the higher load rating will provide you an increased bearing life compared to the standard.

• Is it common for SPW/SPAW/SFCW to come in “fixed” &/or “floating” versions?The NTN design can be either the 'fixed' or 'floating' version. This is accomplished by using snap rings to retain the bearing, moving the snap rings to the appropriate groove will create the desired version. This means a single NTN part number covers both requirements
• Can you substitute an E-Type CRB for a Standard CRB?Yes, as long as you use both the inner & outer rings. When you switch to the E-Type CRB, the higher load rating will provide you an increased bearing life compared to the standard.

• What is the difference between B-type spherical roller bearings and E-type?The B-type spherical roller bearing has asymmetric rollers guided by an inner ring center rib for better skewing control. E-type spherical roller bearing employs larger symmetric rollers for increased load capacity, fast becoming the industry standard. With the recent acquisition of SNR, NTN can provide more E-type spherical roller bearings than ever.
• Does NTN make sealed spherical roller bearings?NTN makes a limited series of sealed spherical roller bearings, the WA series, the MX-W, and various special part numbers. Please contact NTN engineering for more details.

• Are your tapers the same as Timken?Are they interchangeable with Timken? All NTN-Bower tapered roller bearings, as well as NTN tapered roller bearings with the prefix “4T-” or “ET-,” are Timken interchangeable.
• Are tapered bearings case-carburized?All NTN-Bower tapered roller bearings and NTN tapered roller bearings with the prefixes “4T-,” “ET-,” or “E-” are case-carburized. ISO-class tapered roller bearings with a "U" suffix and NTN tapered roller bearings not having a previously mentioned prefix will be through-hardened, although these tend to be larger sizes (8” outer diameter and larger).
• Does NTN make tapered roller assemblies?Both NTN and NTN-Bower make 2- and 4-row assemblies, some of which can be found in the NTN-Bower catalog and the NTN Large Bearing catalog (/E).
• Does NTN make extra precision tapered roller bearings?NTN does make some select sizes of tapered roller bearings in high precision classes (i.e. ABMA classes -3, -0, -00 etc.). Please contact NTN engineering for more details.
• What is the recommended end-play for tapered roller bearings?End-play is application specific, or preset in the case of NA-type assemblies. The machine manufacturers recommendations should be followed. For new designs please contact NTN engineering.

• Does internal clearance affect the bearing precision (C3 vs. P3)?C3 is an internal clearance, or the amount of internal free space between the rolling elements and the raceways of a bearing. P3 does not exist. P6 is an ISO tolerance class equivalent to ABEC-3, or the accuracy the bearing is manufactured to. Clearance does not affect tolerance and tolerance does not affect clearance.
• Explain the difference between C3 and normal clearance?Clearance classes are established by ABMA.C3 is a clearance range one step larger than "C Normal" (sometimes referred to as "C0" in deep groove radial ball bearings).
• Is there a chart that shows radial clearance ranges in both metric & inches?NTN does not generally publish clearance tables with inch dimensions.
• What is preload?Preload is an initial load or "negative clearance" given to a bearing before or during operation. This results in the rolling element and raceway surfaces being under constant elastic compressive forces at their contact points. This has the effect of making the bearing extremely rigid so that even when load is applied to the bearing, radial or axial shaft displacement is minimized.
• Is it safe to use a C3 fit in place of a standard fit?C3 is not a fit, it is an internal clearance. Fit is how tight or loose the shaft and housing hold the bearing in place. In most electric motor rebuild applications a C3 clearance can be used in place of a normal clearance. Contact NTN engineering for other applications.
• What is the difference between ABEC-3 and C3?ABEC-3 is an ABMA tolerance class. C3 is an internal clearance specification. Fit is the relationship between the bearing bore and outside diameters to the housing bore and shaft outside diameter. Tolerance, clearance, and fit are independent dimensions, although in some cases choosing a larger internal clearance can allow you to use a tighter interference fit. Please contact NTN engineering for details.

• What are NTN’s standard greases?2AS (Shell Alvania 2S), 5K (Kyodo Yushi Multemp SRL) and 3AS (Shell Alvania 3S) are considered NTN standard greases. L627 (Mobil Polyrex EM) is the current standard grease for most aftermarket inventory. 5K is the standard for micro-size bearings. 3AS is the standard in bearing units.
• What is good high temperature grease?NTN has close to 700 greases listed. To pick one for a specific application requires more application information.
• Which grease is best suited for most general bearings?The current NTN standard grease for unknown aftermarket applications is L627 (Mobil Polyrex EM). In most cases a quality general-purpose lithium- or polyurea-thickened grease will work.
• How much grease is too much?For general applications a grease fill of 30% of the free space in the bearing is accepted as standard by most manufacturers. Slow speed applications in harsh environments (such as agricultural machinery) can sometimes require a larger fill. High speed applications (i.e. hand tools) can require a lesser fill. Check with NTN engineering for any special requirements.
• What grease can be used when performing maintenance on mounted units?Standard bearing unit inserts are pre-lubed with a lithium soap grease (Shell Alvania 3S). Relubrication should be a grease with the same soap/thickener (lithium).
• What does each grease code identify?The grease code on a bearing number identifies the manufacturer, brand, and fill quantity.
• If I need a bearing to handle high temperatures can I change the grease out to a high temp grease?Unfortunately, just changing the grease will not allow a bearing to handle higher temperatures. A standard steel bearing can withstand temperatures up to 250F. If higher temperatures are needed, the bearing steel needs to also be changed to a temperature-stabilized grade (TS2, TS3, TS4).
• What does FG1 mean?Any part that has the FG1 suffix at the end will come with food-grade solid lube. This suffix is used on both Sentinel series & standard NTN products. NTN uses a food-grade solid lube that is NSF H1 certified for use in all food production areas. If my Sentinel part does not have FG1 at the end will it have a food grade grease? Yes, ALL Sentinel series parts come filled with a food-grade grease that is NSF H1 certified. The FG1 just designates that the bearing comes with a food-grade SOLID LUBE.

Frequently Asked Questions

1. When I search I get a lot of results which do not look like the products I searched for?
2. Can you give me some guidelines when measuring bearings?
3. Is there a method of measuring the clearance in a bearing after fitting and what should it be?
4. My bearing has 2 rubber seals but the number depicts only one, how do I get the correct number of seals?
5. What are C2, C3, C4 and C5 bearings?
6. Can you explain double sealed bearings?
7. LFS Sealed Bearings ~ What you need to know
8. What temperature will oil seals work at?
9. What inside diameter should my oil seal have?
10. What are the different characteristics between deep groove ball bearings?
11. What clearance is necessary between roller and crankshaft components?
12. Do you really carry 2 million bearings in stock?
13. Do you supply automotive bearings?
14. Do you supply shoulder bearings?
15. Do you supply gearbox oil seals?
16. Do you supply washing machine/drum bearing kits?
17. Taxes & Duties. Do I have to Pay them?

Question

“When I search I get a lot of results which do not look like the products I searched for?”

Answer

Different manufacturers use lots of different names for their products. e.g. search for returns a bearing , in the equivalents listing for this bearing is the search term listed as VBF , because this part number contains "" the search result for this is also returned.
At the top of each search result page are a set of filters that can be used to fine-tune the search results.

With competitive price and timely delivery, Beijing SKF sincerely hope to be your supplier and partner.

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Question

“Can you give me some guidelines when measuring bearings?”

Answer

The biggest and most common mistake when taking bearing measurements is to measure metric bearings in inches and likewise inch sized bearings in mm, no amount of searching will produce results for this scenario. Some simple guidelines are:

Generally, metric bearings will have full mm dimensions. Thus 20mm bore x 47mm outside diameter x 14mm width = series metric bearing.

Imperial bearings measured in metric will not have full mm sizes. Thus 12.7mm bore x 28.57mm x 7.87mm is in reality 1/2 inch x 1-1/8 inch x 5/16 inch = KLNJ1/2 series imperial bearing.

There are lots of unit converters available to go from metric to imperial and vice versa. You can also search in Google for "simple unit converter" https://www.google.co.uk there are many free to use online converters. We can of course measure your bearings for you. Please make sure your items are clean and post them to us stating how many of each you require and in what brand.

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Question

“Is there a method of measuring the clearance in a bearing after fitting and what should it be?”

Answer

Feeler gauges need to be used in the bearing to determine what clearance remains between the bearing outer and the rolling elements. This will be stated generally in the manual for the equipment and not by the bearing manufacturers.

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Question

“My bearing has 2 rubber seals but the number depicts only one, how do I get the correct number of seals?”

Answer

Bearing manufacturers generally stamp the bearing number on the bearing and not on the seals, historically numbers on the seals refer to the bearing number and the seal on that side of the bearing only hence the reference of single RS refers to one seal on that side only, for 2 seals 2RS would be the number but its rarely stamped on the seals. The same applies to metal shielded bearings, Z is a single shield reference for one side of the bearing becomes ZZ for 2 seals (Z becomes 2Z in some manufactures numbering schemes).

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Question

“What are C2, C3, C4 and C5 bearings?”

Answer

C3, C4 and C5 bearings are bearings that have an additional internal radial clearance to cope with high-speed environments where excess heat is generated. They are not suited to environments where critical alignment is required from the onset e.g. Where blades and cutters are set up to each other. Applications like motorcycle wheels or bicycle wheels do not require C3 rated bearings. Unless the bearing you are replacing specifically says C3 on it then you should not replace it with a C3 bearing, C3 Bearings are loose to the feel from new and often people complain at the quality of the bearing being poor and having more movement than the one they are replacing. C4 and C5 are even looser still than C3 clearance bearings. This is the characteristic of these higher than normal clearance bearings marked C3, C4 and C5.
C2 marked bearings have less clearance internally than standard bearings and should only be used in applications that specify C2 clearance.

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Question

“Can you explain double sealed bearings?”

Answer

Some manufacturers put the bearing number on the seals, which is fine if you know that a bearing with 2 seals is referred to as 2RS or a ZZ or 2Z.
Customers often refer to these numbers and order a bearing with a number like xxxxRS which, when in the past, we have supplied as a single sealed unit. The customer then complains as they clearly required a 2 sealed bearing. To stop this problem we supply a double-sealed item. The customer can remove the surplus seal if it is not required. This can be done by applying light pressure at the edge of one of the seals with a blunt instrument. A large amount of pressure would need to be applied to a bearing to damage it.

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Question

LFS Sealed Bearings ~ What you need to know

Answer

We sell a lot of LFS bearings, in fact, a great deal more than we sell over the trade counter. It's the misconception that you are getting something better than a standard rubber sealed bearing. It's the opposite way round, LFS seals whilst offering lower friction than RS seals don't offer the same dust or water resistance.

The LFS seal is a none contact seal thus being a lower friction option, the RS is a contact seal and as such offers far better resistance to moisture and dust ingress or foreign matter than the LFS types. Consider your choice carefully, replace LFS with LFS but don't replace RS with LFS as it will undoubtedly lead to premature failure.

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Question

“What temperature will oil seals work at?”

Answer

Nitrile rubber oils seals, the most commonly found seals in engines, gearboxes and general industrial applications have a working temperature range of -22 deg C to +100 deg C (-22 deg Fahrenheit to 212 deg Fahrenheit)

More information on temperature ranges for each material can be found here [Click Here]

For more information, please visit Deep Groove Ball Bearings manufacturer.

Viton oil seals are available in a selection of sizes and can tolerate far higher extremes of temperature between -20 deg C to +200 deg C (-4 deg Fahrenheit to 400 deg Fahrenheit)

The temperature should only be one consideration when selecting an oil seal, the medium in which it must run is also of prime importance and can be checked by clicking Chemical Resistance Table: [Click Here].

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Question

“What inside diameter should my oil seal have?”

Answer

The required inside diameter of an oil seal is the same as the shaft size it will be running on (the seal manufacturers make allowance for the seal to be the correct fit on a shaft).

If you can supply us with the shaft size, outside diameter and width you require we can locate the seal for you and send you a link to it.
If the seal is missing or damaged beyond measuring then simply measure the shaft diameter and the diameter of the bore in the housing into which it fits and as best you can the width of the seal, these will be your inside, outside and width dimensions.

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Question

“What are the different characteristics between deep groove ball bearings?”

Answer

The standards of internal clearance that bearings are manufactured to are quoted by a C then a number or for standard clearance bearings are denoted to be CN clearance which is never stated and places the bearing between C2 and C3 Clearance.
The answer is that as the number gets higher the internal clearance between all the moving parts gets larger to cope with hot and high-speed environments better than standard or C3 bearings (C3 having slightly more clearance than standard) bearings would.
In principle as a bearing gets hot with speed or its environment then the parts expand, whilst expanding the distances between all the moving parts gets smaller.
Standard bearings are what are known as CN clearance but this is never stated in the bearing number thus CN would normally be stated as just .
C2 is less than normal so the bearing is tighter (designed for slower-moving more precise applications that require little or no play in the bearings where the temperature remains fairly constant.
C3 is designed for hot running environments; engines etc. where the bearing temp could reach 100deg or more.
C4 more extreme temperature applications and higher speed environments.
C5 the highest clearance bearing available, are extremely loose to start and can knock until at operating speeds and temperature.
For these reasons the materials and designs vary to accommodate these characteristics.

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Question

“What clearance is necessary between roller and crankshaft components?”

Answer

As the diameter of the crankshaft increases the clearance will stay proportional to the diameter. It comes under ISO standards of limits and fits. It will be in the back of a Zeus book or similar, Google will show some limits and fits tables. Our limits and fits tables can be found here [Click Here].

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Question

“Do you really carry 2 million bearings in stock?”

Answer

In reality, we probably have more! We now have a purpose-built 20,000 square feet UK stock holdings in the North West of England based in Leigh at the heart of Lancashire and receive deliveries daily from the US and Europe. Additionally, we have a large storage unit in Bolton where we store bulk stocks should we need them. We supply SKF, NSK, RHP, FAG, INA, IKO, NTN, SNR and many other major brands and have access to a huge network of National and International bearing distributors should we need them.

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Question

“Do you supply automotive bearings?”

Answer

The bearings we supply are suitable for most applications however we do not supply manufacturers specific bearings. E.g. if you have a bearing with a Renault part number on it then it’s not likely we can cross-reference it to anything standard. By the same token if you measure the bearing it will most likely be a standard bearing. Manufacturers do this and sell spares as OEM parts at a premium. (Original Equipment Manufacturer). Because there is such a phenomenal variety of bearings for cars we do not have access to cross-reference databases for these bearings. We do however sell wheel bearing kits for a very wide range of cars from stock. [Click Here]

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Question

“Do you supply shoulder bearings?”

Answer

If you meant "flanged bearings" then yes we do, they can be found [here] other than that we do not have a database that provides the necessary information, however, if you can provide the bearing number, I am sure we will be able to obtain the bearing required.

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Question

“Do you supply gearbox oil seals?”

Answer

Yes, we do, our oil seals are used in many types of gearbox, unfortunately, we do not have a database that provides this information, however, you can easily identify an oil seal from the shaft diameter it runs on, the outside diameter of the seal or the diameter of the housing it fits into and its's width.

As you can imagine there are thousands of makes and models of vehicles, fortunately, they all generally, with the exception of a few manufacturers, fit standard oil seals which can be identified by their sizes. If you can provide the dimensions of the seal, i.e. bore, diameter and width, I am sure I will be able to obtain the seal required.

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