Frequently Asked Questions
- When I search I get a lot of results which do not look like the products I searched for?
- Can you give me some guidelines when measuring bearings?
- Is there a method of measuring the clearance in a bearing after fitting and what should it be?
- My bearing has 2 rubber seals but the number depicts only one, how do I get the correct number of seals?
- What are C3 bearings?
- Can you explain double sealed bearings?
- LFS (Low Friction Seals) sealed bearings ~ What you need to know.
- What temperature will oil seals work at?
- What inside diameter should my oil seal have?
- What are the different characteristics between deep groove ball bearings?
- What clearance is necessary between roller and crankshaft components?
- Do you really carry 2 million bearings in stock?
- Do you supply automotive bearings?
- Do you supply shoulder bearings?
- Do you supply gearbox oil seals?
- Do you supply washing machine/drum bearing kits?
- Taxes and Duties - do I have to pay them?
"When I search I get a lot of results which do not look like the products I searched for?"
Different manufacturers use lots of different names for their products. e.g. search for 6204 returns a bearing 3204, in the equivalents listing for this bearing is the 6204 search term listed as VBF 3056204, because this part number contains "6204" the search result for this is also returned.
At the top of each search result page are a set of filters which can be used to fine tune the search results.
"Can you give me some guidelines when measuring bearings?"
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 25mm bore x 47mm outside diameter x 14mm width = 6204 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 really 1/2 inch x 1-1/8 inch x 5/16 inch = KLNJ1/2 series imperial bearing.
There are a number of unit converters available to go from metric to imperial and vica versa.
You can also search in in Google for "simple unit converter" https://www.google.co.uk IT'S FREE and very useful.
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.
"Is there a method of measuring the clearance in a bearing after fitting and what should it be?"
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.
"My bearing has 2 rubber seals but the number depicts only one, how do I get the correct number of seals?"
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 6205RS refers to one seal on that side only, for 2 seals 2RS would be the number but its rareley 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).
"What are C2, C3, C4 and C5 bearings?"
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.
"Can you explain double sealed bearings?"
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.
LFS Sealed Bearings ~ What you need to know.
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.
"What temperature will oil seals work at?"
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]
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)
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]
"What inside diameter should my oil seal have?"
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 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 hole 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.
"What are the different characteristics between deep groove ball bearings?"
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 principal 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 6205CN would normally be stated as just 6205.
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
"What clearance is necessary between roller and crankshaft components?"
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]
"Do you really carry 2 Million bearings in stock?"
In reality we probably have more! We have 3 large UK stock holdings and receive deliveries daily from the US and Europe. 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.
"Do you supply automotive bearings?"
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]
"Do you supply shoulder bearings?"
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.
"Do you supply gearbox oil seals?"
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, it's outside diameter 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.
"Do you supply washing machine/drum bearing kits?"
We do supply such bearings and seals, however, you will need to dismantle the machine first in order to obtain the bearing numbers and seals sizes.
Taxes & Duties. Do I have to Pay them?
If you are in the UK or European Union you will be required to pay VAT on goods and postage as detailed on HMRC website. If you are in the EU and have a valid VAT number we can sell to you exempt of VAT subject to us verifying your VAT status. Rest of the world purchases and shipments are exempt of VAT.