FAQ

Unfortunately, there is never an explicit warranty with bearings. Bearings do eventually wear out and every application, setup and operator is different. It is very difficult to calculate life expectancy without having extremely detailed data about your application. However, Boca Bearings has been in business since 1987 and we stand behind our product 100%. We will always replace or exchange any bearings that we determine to have failed prematurely.

If you have gone through the cleaning steps outlined below and your bearings begin to feel gritty or notchy to the touch, they should be replaced. When bearings sit idle for a long time they must be protected from any and all moisture. This is a common problem when storing small RC engines. If any moisture has gotten to the bearings, they will need to be replaced before using the engine again.

1) Soak your bearings in mineral spirits or paint thinner to remove any grease or particulates. 2) Blow bearing out with compressed air. 3) Place a light drop of oil on the bearing. 4) Give the bearing a spin, if they still feel rough repeat steps 1-3

Yes, we do ship internationally. After placing items in your shopping cart, proceed to the checkout area. Complete the Shipping and Billing information, including selecting your country. If your country is not in our drop-down list, we are unable to ship orders to that country. We ship orders via US Mail, FedEx or UPS. The most reliable way to ship internationally is by UPS and Fedex. There are, however, more duties and taxes associated with these carriers when the package arrives in your country. If you are not familiar with the customs laws and fees in your country, please check with your local customs office for more information. US Mail is less expensive but in our experience, not as reliable because they are not the ones bringing the package to your doorstep. 
Please note that in your destination country you may need to pay additional import fees, taxes, brokerage fees, and handling fees to receive your order.  This is not a charge Boca Bearings charges or  has control over

Silicone Nitride Si3N4 full ceramic bearings with a PTFE cage retainer are recommended for most cryogenic applications. 

Bearings are usually measured with either a digital or dial caliper.  The sequence of the measurements are always Inside Diameter x Outside Diameter x Width (IDxODxW).

There is no true waterproof seal for bearings. Bearing seals are primarily designed to retain the lubrication inside the bearing. Most bearing seals are considered water repellant and will keep moisture out of the internal components, but they will not prevent water from entering the bearing if it is submerged. If you require a bearing that can operate submerged in a liquid, we would suggest a ceramic hybrid or full ceramic bearing depending on the operating environment.

If your front bearing has two rubber seals you should not remove them. These bearings have their own grease and can help stop oil leaks. If your bearing has two shields, we recommend you remove one of them. (For instructions on removing your shields, see the next section) Your rear bearing should be open on both sides to allow as much fuel as possible to pass through and act as a lubricant. You may however want to leave one shield on, in the rear which would help to protect the rest of the engine from any foreign matter getting through. This should not be done with one seal. If you find your engine is stingy in getting fuel to the rear, you should definitely leave the bearing open.

For fixed metal shields you should use an awl. Place the awl on the shield toward the outer race. Punch down lightly until you make a small hole. Then peel the shield back with the awl. Removable metal shields are held in place with a retaining ring. Run a sewing needle along the inside of the outer race to pop out the retainer. Once the retainer is removed the shield should pop out with a light tap. To remove a rubber seal use a pen knife or sharp pointed object. In most cases the rubber cannot be reused.

Here is an instructional video:
How to properly remove shields and seals

Precision ball bearings are manufactured to standards established by the Annular Bearing Engineers Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). The ABEC and ISO bearing standards are primarily concerned with bearing tolerances. The tolerance is the permissible deviation from a specified value of a structural dimension. The higher the ABEC rating the closer the part is to being dimensionally perfect. For more information about ABEC ratings see info.

1) Soak your bearings in mineral spirits or paint thinner to remove any grease or particulates. You can also spray your bearings with Brake Cleaner.  This will flush any debris out of your bearings.  2) Blow bearing out with compressed air. 3) Place a light drop of oil on the bearing. 4) Give the bearing a spin, if they still feel rough repeat steps 1-3.

Radial Play refers to the fit or clearance of the balls in the bearing. The normal range is from C2 to C5. C2 would be the tightest fit and would not have much room allowed for expansion of the balls or misalignment. C5 would be the loosest, where the balls are undersized to allow for some expansion as the bearing heats up or misalignment of the application.

Any bearing you search for on this site will display technical data including: Bearing Material, Enclosure Type, RPM Data, Load Rating etc. If you need more detailed information about bearing characteristics, bearing design or bearing life.  Please see our Engineering Guide.

The Axial play of a radial bearing is about 5% of its Radial Load in a Thrust Load capacity.

No, traditional steel bearings always need lubrication to have a long life and lubrication will always be reduced over time as it will dissipate with use. How fast the lubrication dissipates varies greatly depending on RPM, operating temperature, operating environment and set up. If you have a particularly high temp application we would need to know the operating temperature to suggest suitable lubrication.

All of our sealed bearings are considered maintenance free and lubed for the life of the bearing. This is because they are packed with a heavy duty, lithium based grease. When the lube fully dissipates it is generally time to replace the bearing. However this does not mean that you cannot extend the life of the bearing. When they start to feel gritty you can remove the seals and soak the bearings in our Clean Touch overnight. When you remove the bearings from the cleaner, blow the bearings out with compressed air.  Then you can re-lube them with your lube of choice. Just keep in mind that the thinner the lube is, such as oil vs. grease, the quicker it will dissipate and need to be reapplied.

Maintenance depends on the type of enclosures and lubricants your bearings have. Rubber sealed or Ultra sealed bearings require no maintenance and the lube is good for the life of the bearing. Metal shielded bearings that use either grease or oil should be constantly maintained and frequency level will vary depending on your application. Oil dissipates faster than grease, so typically shielded bearings using oil as lubrication will require constant care. Developing a regular maintenance schedule will substantially add to the life of your bearing.

Unfortunately every operator, setup and operating environment is very different so it is difficult to quantify an exact improvement in performance. But in general ceramic bearings are lighter, stronger and faster. Typically you will see about 2-3 times the life out of a ceramic bearing as compared to a standard bearing. This is because ceramic is harder than steel in ball form; it is 3-4 times the Rockwell hardness of a steel ball. As far as performance is concerned, a ceramic bearing is capable of producing 50% more RPM than a standard bearing. This is due to the fact that the ceramic ball is virtually frictionless because it is non-porous, unlike steel which has pores and generates both heat and friction. Ceramic bearings will also not micro-weld due to insufficient lube or arcing. All of these characteristics add up to a better performing vehicle that can accelerate faster and requires less energy to achieve peak RPM.

No, full ceramic bearings can be run completely dry. They do not need lubrication to run. Ceramic is non-porous, unlike steel, as a result it is virtually frictionless. Ceramic also dissipates heat very quickly, which is the same reason they use it on the underside of the space shuttle. Because there is no heat buildup and virtually no friction, full ceramic bearings can be run completely dry. They can be cleaned out with regular tap water or any cleaner, they are impervious to corrosion and can operate in a vacuum environment.

Unfortunately, it is not an exact science. Most bearings are packed in thick, viscous grease or with a light weight oil. As a result the bearing generally will not free spin to the touch. Over time as the lube thins out, and warms up during each use, the bearing will become much freer. So all you need to do is to use the bearing normally and it will break in naturally. The more you use the bearing the more broken in it becomes until eventually it is so broken in that it is time to replace it.

A radial deep groove bearing is capable of handling an axial (thrust) load that is 5% of the radial load. 

Ceramic hybrid bearings can handle the same loads as a steel bearing and full ceramic bearings can handle 10-15% less than steel. The full ceramic bearings are not as tolerant as steel to shock loads or excessive vibration.

All Orange Seal bearings with an LD (lube dry) in the part number are supplied dry, without grease or oil. AF2 in the part number means light oil and NB2 in the part number means a light duty grease. If your bearings are already dry they will not require any further handling. They can be run completely dry or you can add a light drop of oil to the outside seal and work the oil into the bearing. Dry bearings can be more noisy but a light drop of oil will quiet them right down. If your bearings came packed in grease or oil and you would like to clean out your bearings, you can remove the seals and soak the bearings in our Clean Touch overnight. Blow the bearings dry the next day or let them air dry.  Please do not soak the seals in any type of solvent, this may warp or damage the seal.

Not really, because most fishing enthusiasts use oil as lubrication it is very difficult to retain it in the bearing even with seals. The seals will prolong the use of the bearing before re-oiling however. It is advisable to regularly maintain your bearings, by doing so you will extend the life and the performance of the bearings.

Yes, while ceramic hybrid bearings do not need any lubrication to operate the steel races will have a longer life if they have a slight amount of light oil on a regular basis.

We always suggest testing ceramic bearings by putting them under load. Fishing reel bearings are relatively small and ceramic is much lighter than steel so there is just not enough mass to see a prolonged free spin without a load attached to the bearing. The flick test seems to result in a perception that a ceramic bearing does not spin as long as a steel bearing, but as soon as you put both bearings under load the difference is noticeable. New bearings will require a short break in period, so comparing new bearings to old worn in bearings is not an apples-apples comparison.  We typically just attach an awl to a bearing and give it a spin like shown in this

spin test video.

No, full ceramic bearings can be run completely dry. They do not need lubrication to run. Ceramic is non-porous, unlike steel, as a result it is virtually frictionless. Ceramic also dissipates heat very quickly, which is the same reason they use it on the underside of the space shuttle. Because there is no heat buildup and virtually no friction, full ceramic bearings can be run completely dry. They can be cleaned out with regular tap water or any cleaner, they are impervious to corrosion and can operate in a vacuum environment.

Depending on the bearing size and our current inventory this will vary from bearing to bearing. The best thing to do is contact us and let us know the make and model of your reel and we will let you know if the shields are removable for the specific bearing for your reel. You can take a look at this page on our website to see how to remove the shields. http://www.bocabearings.com/bearing-info/fishing-reel-bearing-maintenance-installation-guide

On the removable shields there are c-clips to hold them in place.  We do have some bearings that have fixed shields that can not be removed and reinstalled.  Please contact us if having a specific type of shield is required

Yes, the stocked greased bearings can be used as is and will give you great performance.

Unfortunately there is never an explicit warranty with bearings. Bearings do eventually wear out and every application, setup and operator is different. It is very difficult to calculate life expectancy without having extremely detailed data about your application. But Boca Bearings has been in business since 1987 and we stand behind our product 100%. We will always replace or exchange any bearings that we determine to have failed prematurely. As a rule of thumb we would say:
 
Our Econo Power shielded bearings are comparable to what comes stock with your vehicle, so you should expect the same life as those that you get right out of the box with your car. Because these are shielded bearings they will require maintenance to get a long life. You will want to clean and re-lube them regularly to extend the life or you will have to replace them often.
 
Our Green Seal & Ultra Seal bearings however are considered maintenance free and lubed for the life of the bearing. You do not have to ever clean or re-lube these bearings at all and they should last at least twice as long as your stock bearings.
 
And finally our Ceramic Lightning Yellow Seal & Ultra Seal bearings are also considered maintenance free and lubed for the life of the bearing. But because the ceramic ball is so much harder than steel you should expect about 3-4 times the life of your stock bearings.

The clutch bell is a constant source of problems due to excessive heat buildup. The heat levels cause the steel balls to expand and the retainer is subjected to a tremendous amount of stress, as a result the bearings fail prematurely. The best solution is to use a bearing with a ball that will not expand and to do away with the retainer altogether. We offer 4 different RC Car & Truck Clutch Bell Bearing Kits.

Place your engine housing in an oven at 325°-350° for 5 to 10 minutes. When you remove it from the oven your old bearings should fall right out, if not heat the engine a little longer. We also suggest you place your bearings inside a ziploc bag and keep them in the freezer overnight. Then slip the bearings into the engine while it is still slightly warm. These instructional videos show how to remove and install RC Nitro Engine Bearings Part 1, how to remove and install RC Nitro Engine Bearings part 2.

Firstly the different colored seals do indicate which the open side on the bearing is. The green seal is the one to remove to expose the open side. However, on the front bearing there is no need to remove either seal. Keeping both seals on offers better protection for the bearing. These bearings are lubed with grease and the seals will keep the grease in for the life of the bearing so there is no need to worry about lubrication. With regard the rear bearing both seals can be removed if needed and is probably advisable.

Ceramic hybrids that have steel races and ceramic balls do not offer a significant weight savings as only the balls are ceramic. Full ceramic bearings however do offer a significant weight savings by about 2/3 the weight of traditional steel bearings. Unfortunately full ceramic bearings are not appropriate for many RC applications.

Ceramic Metal Shield bearings are metal shielded and offer the least resistance of the three. These bearings need frequent cleaning but will give you the best performance. Not recommended for dirty or wet environments, Ceramic Yellow Seal are rubber sealed bearings and offer the best protection against dirty and wet conditions. The bearings are maintenance free and are recommended for extreme conditions. Because they are contact rubber seals there is a certain amount of friction, which will lessen the more they are used and Ceramic Ultra Seal have a PTFE seal that sits under a metal shield and are maintenance free and offer lower friction than the rubber seals. They require a small amount of break in time and are recommended for on-road or indoor use only. They should not be run on water or muddy conditions as the seals are not as waterproof as the rubber seals.

Rubber sealed bearings will always offer the most protection and be the most maintenance free.

The only bearings that need to be lubed occasionally are the metal shielded bearings, and they need to be cleaned every 4 - 5 races depending on the length of each race.

Our green seal bearings are water resistant, not waterproof. They are the best bearings available for off-road racing, through mud, water and dirt. However if submerged for a length of time it could result in corrosion and subsequent failure. As long as the seals are kept intact they will last you a long time without maintenance. If you require bearings that are going to be submerged in water please contact us directly to discuss specialty bearings.

Ceramic Bearings can refer to several things. Ceramic Bearings could mean that the balls themselves are ceramic that get used in a hub assembly. Ceramic Bearings could refer to what is more typically known as ceramic hybrid bearings, which are bearings where the inner and outer race are metal, and the balls in the bearing are ceramic. Or Ceramic Bearings could refer to what is known as a full ceramic bearing, which is when the races and balls are made of ceramic material. 

Ceramic hybrids are lighter weight, capable of achieving higher RPM's than traditional steel bearings, have lower coefficient of friction than steel bearings, and sustaining higher operating temperatures than traditional bearings. The ceramic ball will never corrode and cannot weld to the metal races eliminating one of the most common points of bearing failure.

Full ceramic bearings are for those cyclists looking to make their bikes as mechanically efficient as possible. The full ceramic bearings are lighter weight than traditional steel bearings, and ceramic hybrid bearings. The coefficient of friction for full ceramic bearings is lower than other bearings, meaning that it is mechanically more efficient.  Full ceramic bearings are much harder than either standard bearings or ceramic hybrid style and may wear out much faster.

 Yes, you should run bike bearings with grease for a few reasons. If you are using traditional steel bearings grease is required to dissipate heat. If heat is not properly dissipated in a steel bearing the bearing will seize and fail. For ceramic hybrid and full ceramic bearings grease is recommended but not required. The grease in a bearing will help capture dirt and particulates and keep them away from rolling elements of the bearing. If you choose to run ceramic hybrid and full ceramic bearings without grease then more frequent cleaning is recommended.

Full ceramic bearings can break when subjected to high loads. Specifically the ceramic races do not hold up under loads as well as ceramic balls do. Typically any environment where there are impact loads is not ideal for full ceramic bearings. We also do not recommend using full ceramic bearings in bottom brackets of bikes unless the rider is 150 lbs or less in weight.

No, full ceramic bearings can be run completely dry. They do not need lubrication to run. Ceramic is non-porous, unlike steel, as a result it is virtually frictionless. Ceramic also dissipates heat very quickly, which is the same reason they use it on the underside of the space shuttle. Because there is no heat buildup and virtually no friction, full ceramic bearings can be run completely dry. They can be cleaned out with regular tap water or any cleaner, they are impervious to corrosion and can operate in a vacuum environment.

The ceramic hybrids can handle the same loads as a steel bearing and full ceramics can handle 10-15% less than steel. The full ceramics are not as tolerant as steel to shock loads, impact or excessive vibration.

Unfortunately every operator, setup and operating environment is very different so it is difficult to quantify an exact improvement in performance. But in general ceramic bearings are lighter, stronger and faster. Typically you will see about 2-3 times the life out of a ceramic bearing as compared to a standard bearing. This is because ceramic is harder than steel in ball form; it is 3-4 times the Rockwell hardness of a steel ball. As far as performance is concerned, a ceramic bearing is capable of producing 50% more RPM than a standard bearing. This is due to the fact that the ceramic ball is virtually frictionless because it is non-porous, unlike steel which has pores and generates both heat and friction. Ceramic bearings will also not micro-weld due to insufficient lube or arcing. All of these characteristics add up to a better performing vehicle that can accelerate faster and requires less energy to achieve peak RPM.

The temperature that a bearing can operate in is determined by all of its components. If the races and rolling elements can withstand 200 degrees Celsius, but the retainer can only operate in 150 degrees, then the bearing can only operate in 150 degrees.

A machine-tool spindle must provide high rotational speed, transfer torque, power to the cutting tool and have reasonable load capacity and life.

High-Speed Spindle Bearings available are Tapered Roller, Roller Bearing and Angular Contact Ball Bearings. 

Selection criteria depends on the spindle manufacturers specifications and the speed needed for cutting metal. Things like operating temperature ranges, max RPMs can be factors. 

Angular contact ball bearings provide precision, load-carrying capacity, and the speed needed for cutting metal. Angular contact ball bearings also provide both axial and radial load-carrying capacity when properly preloaded.

Tapered Roller bearings offer higher load carrying capacity and greater stiffness however, tapered roller bearings do not allow the high speeds typically required. 

A dN number is the benchmark used for the maximum speed a bearing can achieve. The dN number is derived by multiplying the mean bearing diameter by the speed in rpm. For a high-speed spindle using ball bearings, dN numbers can get up to 1,500,000.

It is the nominal angle between the ball-to-race contact line and a plane through the ball centers, perpendicular to the bearing axis.

The contact angle determines the ratio of axial to radial loading possible, with radial loading being the primary benefit. Typically, contact angles of 15°, and 25º are available. The lower the contact angle, the greater the radial load-carrying capacity. Conversely, the higher the contact angle the higher the axial loading capacity.

ABEC standards define tolerances for major bearing dimensions and characteristics. They are divided into mounting dimensions (bore, ID, and width), and bearing geometry. Accuracy ratings range from a low of ABEC 1, for a general-purpose bearing, to a high of ABEC 9, for a high precision bearing used in a high speed spindle.

Light, Medium and Heavy pre-loads are available. Light preloaded bearings allow maximum speed and less stiffness. These bearings are often used for very high-speed applications, where cutting loads are light.

Spindle stiffness is achieved for metal cutting by stacking multiple bearings to increase the load carrying capacity and increase spindle stiffness. Back-to-back, “O”, or “DB” mounting is the most common technique. In this configuration, the inner races are relieved, then clamped together, eliminating the relief clearance. This results in the correct preload and is a configuration most suited to good accuracy and rigidity.

Hybrid ceramic bearings use silicon nitride material to make precision balls. The ceramic balls, when used in an Angular contact ball bearing, offer distinct advantages over typical bearing-steel balls. Ceramic balls allow the spindle to achieve up to 50% more RPM, dissipate heat quicker and have a much lower rate of thermal expansion.

C-HIP Motorcycle Bearings are a line of bearings that utilizes Si3N4 Silicon Nitride Balls that are made with a more rigorous manufacturing process than ceramic balls used in other bearing lines. The HIP stands for Hot Isostatic Press which is a hotter and higher density process that makes the ceramic ball more dense and durable than standard Si3N4 balls. 

Ceramic hybrid bearings are lighter weight, capable of achieving higher RPMs than traditional steel bearings, have lower coefficient of friction than steel bearings while sustaining higher operating temperatures than traditional bearings. The ceramic ball will never corrode and cannot weld to the metal races eliminating one of the most common points of bearing failure. 

Full ceramic bearings are not ideal for motorcycle applications. The full ceramic bearings will not hold up under impact loads. Specifically the ceramic races are likely to crack under high impact loads. It is recommended to use a ceramic hybrid or steel bearing instead.

Yes, you should run motorcycle bearings with grease for a few reasons. If you are using traditional steel bearings grease is required to dissipate heat. If heat is not properly dissipated in a steel bearing the bearing will seize and fail. For ceramic hybrid bearings grease is recommended but not required. The grease in a bearing will help capture dirt and particulates and keep them away from rolling elements of the bearing. If you choose to run ceramic hybrid bearings without grease then more frequent cleaning is recommended. 

Ceramic Bearings can likely refer to two things in reference to motorcycles. Ceramic Bearings could mean that the balls themselves are ceramic. Ceramic Bearings could also refer to what is more typically known as ceramic hybrid bearings, which are bearings where the inner and outer race are metal, and the balls in the bearing are ceramic.

Stainless steel must contain at least 10.5 % chromium. It is this element that reacts with the oxygen in the air to form a complex chrome-oxide surface layer that is invisible but strong enough to prevent further oxygen from "staining" (rusting) the surface. Higher levels of chromium and the addition of other alloying elements such as nickel and molybdenum enhance this surface layer and improve the corrosion resistance of the stainless material.

304 contains 18% chromium and 8% nickel. 316 contains 16% chromium, 10% nickel and 2% molybdenum. The "moly" is added to help resist corrosion to chlorides (like sea water and de-icing salts)

Grade 440C stainless steel is a high carbon martensitic stainless steel. It has high strength, moderate corrosion resistance, and good hardness and wear resistance. Grade 440C is capable of attaining, after heat treatment, the highest strength, hardness and wear resistance of all the stainless alloys. Its very high carbon content is responsible for these characteristics, which make 440C particularly suited to such applications as ball bearings and valve parts.

A popular grade of stainless steel is stainless steel 316 is generally composed of 16 to 18% chromium, 10 to 14% nickel, 2 to 3% molybdenum, and a small percentage of carbon. Adding molybdenum to stainless steel 316 increases its corrosion resistance compared to other grades of stainless steel. The addition of other alloys further enhances its properties. The properties and characteristics of stainless steel 316 make it the second-most widely used stainless steel grade after stainless steel 304. It is used in corrosive environments such as chemical plants, refineries, and marine equipment.

Stainless steel 316L has a lower carbon content and is used in applications that subject the metal to risks of sensitization. The higher carbon variant is stainless steel 316H, which offers greater thermal stability and creep resistance. Another widely used grade of stainless steel 316 is the stabilized 316Ti. Stainless steel 316Ti offers better resistance to intergranular corrosion.

There are several "types" of stainless steel. The 300 series (which contains nickel) is NOT magnetic. The 400 series (which just contains chromium and no nickel) ARE magnetic.

When the amount of chromium (in an iron matrix) exceeds 10 ½%, a complex chrome oxide forms instantaneously that prevents the further diffusion of oxygen into the surface and results in the "passive" nature of stainless steel and its resistance to oxidation (or corrosion). A chemical "dip" into 10% nitric acid plus 2% hydrofluoric acid bath will enhance the development of this "passive" oxide.

YES. Stainless steel is easily welded, but the welding procedure is different than that used with carbon steel. The "filler" rod or electrode must be stainless steel. 

YES. The 300 series stainless steel can be "hardened" BUT only by "work hardening." That is by cold working the material, either by cold rolling down to lighter and lighter gauges, or by "drawing" through a die or other size altering operation. "Annealing" stainless steel will REMOVE the work hardening effect. YES and NO. The 400 series have two different stainless steel structures. One is called "ferritic" (409, 430, 434. 439) which cannot be hardened by heat treatment. The other is called "martensitic" (403, 410, 416, 420, & 440 A,B,C) which CAN be hardened by heat treatment. 

Yes. Stainless steel has excellent properties at both extremes of the temperature scale. Stainless steel can be used down to liquid nitrogen temperatures and up to about 1800° F.

420 stainless steel is a martensitic higher carbon version of types 410 and 416 stainless that can be hardened by heat treatment. It contains a minimum of 12 percent chromium, sufficient to give 420 corrosion resistance properties.