All you need to know about 608 bearings : Complete guide

Introduction to 608 bearings

The 608 ball bearing is one of the most commonly used types of ball bearing in the world. Its standard design and versatility make it a preferred choice for many applications, including sports equipment, household appliances and industrial machinery. This bearing features an inner diameter of 8 mm, an outer diameter of 22 mm and a width of 7 mm.

Why is the 608 bearing popular?

The 608 bearing is popular for several reasons. Firstly, its standardized dimensions enable easy interchangeability and wide availability on the market. Secondly, it offers excellent value for money, making it affordable for many industrial and commercial applications. What's more, its ability to withstand high speeds and moderate loads without compromising durability makes it a reliable component in a variety of mechanisms.

Bearing 608 technical specifications

608 bearing types: 2RS, ZZ and open bearings

The 608 2RS ball bearing is equipped with two rubber seals, offering optimum protection against dust, water and other contaminants. It is particularly suited to applications such as skateboards, roller skates and environments where exposure to contaminants is frequent.

The 608 ZZ ball bearing, on the other hand, features two metal shields, reducing friction while offering moderate protection against contaminants. This type of bearing is ideal for electric motors, fans and equipment requiring high-speed performance.

Finally, the 608 open ball bearing, without seals or shields, features minimal friction and is easy to clean and lubricate. It is ideally suited to 3D printers, laboratory equipment and devices requiring frequent maintenance.

Materials used in manufacture

608 bearings are manufactured from a variety of materials, according to the specific needs of each application:

The thickness of 608 bearings varies according to the materials used, offering options to suit a variety of technical requirements.

High-chromium steel is the most commonly used material, due to its robustness and resistance to wear.

Ceramic is used for applications requiring high performance at higher speeds and lower friction. Ceramic bearings are also lighter and more resistant to corrosion.

Composite materials are sometimes used for specific applications requiring particular properties such as lightness or better resistance to certain chemical environments.

Load and speed ratings

608 bearings are designed to support moderate loads and high speeds, making them suitable for a wide range of industrial and commercial applications. Here's an overview of their capabilities:

• Radial load capacity: Approx. 1360 N (Newton) for static load and approx. 3350 N for dynamic load.

• Limiting speed: Up to 34,000 rpm (revolutions per minute) with oil lubrication, and approx. 28,000 rpm with grease lubrication.

Typical applications for bearing 608

Use in skates and rollerblades

The 608 bearing is particularly popular in the sports and leisure industry, notably in skates and rollerblades. Its design enables smooth, effortless rotation, essential for high-quality performance. 608 bearings help to reduce friction and increase speed, providing an optimal gliding experience. Thanks to their robustness, these bearings can withstand the frequent shocks and impacts encountered when using this equipment.

Industrial applications

608 bearings also play a crucial role in a variety of industrial applications. Their ability to support moderate loads and operate at high speeds makes them ideal for many types of machinery and electrical equipment. For example, they are used in small industrial equipment where they ensure precise movement and low friction, increasing machine efficiency and durability. In electric motors, industrial fans and other equipment, 608 bearings ensure smooth, quiet operation, their ability to run at high speeds without overheating being a major asset.

Hand-held power tools: Used in drills, saws, sanders and other hand-held power tools, 608 bearings guarantee reliable performance and long equipment life.

Other specific uses

In addition to sports and industrial applications, 608 bearings can be found in many other specific applications. For example, they are often used in 3D printers to enable precise movement of moving components, their low friction and precision being essential for producing high-quality prints. In small drone motors or electric motors in household appliances, 608 bearings ensure stable, efficient operation. What's more, in some medical equipment, their reliability and durability are crucial to ensure continuous, trouble-free operation.

Advantages and disadvantages of 608 bearings

Advantages of 608 bearings

The 608 bearing is widely appreciated for its many advantages, making it a popular choice for a variety of applications:

• Durability: Made from high-quality materials such as steel or ceramic, the 608 bearing offers long service life even under heavy-duty conditions.

• Performance: Thanks to its optimized design, it enables smooth operation with low friction, improving the performance of the devices and machines in which it is integrated.

• Cost: The 608 bearing is relatively inexpensive, making it an economical option for many users and industries. Its value for money is one of its main assets.

Disadvantages of 608 bearings

Despite its many advantages, the 608 bearing has certain limitations:

• Load limitations: Although it can support moderate loads, it is not ideal for applications requiring the support of very heavy loads. In such cases, more robust bearings may be required.

• Speed limitations: Although capable of operating at high speeds, there are bearings specially designed for extreme speeds that outperform 608 bearings in these conditions.

What are the best-known brands of 608 bearings?

Among the most reputable brands for 608 bearings are :

• SKF: One of the world's leading bearing manufacturers, SKF is known for the quality and durability of its products.

• NSK: A Japanese brand renowned for innovation and precision in bearing manufacturing.

• FAG: Another benchmark brand, offering reliable, robust bearings, particularly for industrial applications.

• NTN: Another popular Japanese brand, offering a wide range of high-performance bearings.

• Schaeffler (INA/FAG): German industrial group, specialized in high-quality bearings for a variety of industrial and automotive applications.

Care and maintenance of 608 bearings

Maintenance frequency

The frequency with which 608 bearings need to be serviced depends greatly on the application and conditions of use. In sports and leisure applications, such as skates and rollerblades, bearings should be cleaned and lubricated after 30 to 50 hours of use, or more frequently if used intensively or in dusty environments. In industrial applications, bearings used in machinery or equipment should be inspected and serviced at least every six months, or more often if operating conditions are severe. For domestic appliances and other light-duty applications, annual maintenance is often sufficient, unless signs of malfunction appear.

Cleaning techniques

To prolong the life of 608 bearings and maintain their performance, regular cleaning is essential. Carefully remove bearings from their location using appropriate tools to avoid damaging the bearing or its housing. If possible, dismantle bearings by removing seals or dust covers to gain access to the balls and cages. Use a bearing cleaner or solvent such as isopropyl alcohol to remove dirt, grease and debris. Place the bearings in a container containing the cleaner and shake gently to dislodge contaminants. After cleaning, allow bearings to air-dry completely or use a lint-free cloth, avoiding hot-air dryers which can damage bearing materials.

Recommended lubrication products

Proper lubrication is crucial to minimize friction and wear on 608 bearings. Here are some recommended products:

• Greases: Lithium- or polyurea-based greases are commonly used for 608 bearings. They offer good protection against moisture and long-lasting lubrication.

• Oils: High-quality light oils, such as special bearing oils or fine machine oils, are ideal for high-speed applications. They need to be applied more frequently than greases.

• Solid lubricants: In specific environments, solid lubricants such as PTFE can be used to reduce friction without the need for frequent reapplication.

Frequently asked questions about 608 bearings

What are the dimensions of a 608 bearing?
The 608 ball bearing has standardized dimensions: an inner diameter of 8 mm, an outer diameter of 22 mm and a width of 7 mm. These dimensions make them compatible with a wide range of applications in fields as varied as sports, industry and household appliances.

How do I remove a 608 bearing?
Extracting a 608 bearing requires specific tools to avoid damaging the shaft or the bearing itself. Here are the steps to follow:

1. Use a bearing extractor adapted to the size of the bearing to grasp the bearing without forcing.

2. Slowly turn the extractor until the bearing releases from its location.

3. If the extractor is not available, a thin screwdriver and rubber mallet can also be used, tapping gently to remove the bearing without damaging it.

How to insert a 608 bearing?
To insert a 608 bearing correctly:

1. Clean the housing thoroughly before insertion.

2. Place the bearing in its housing.

3. Use a press tool or rubber mallet to press the bearing in, applying even pressure and ensuring that it remains straight. avoid hitting the bearing directly to avoid damaging the balls or rings.

How do I lubricate a 608 bearing?
Lubrication is essential to ensure the bearing's longevity and smooth operation. Follow these steps:

1. Clean the bearing to remove dust and old lubricants.

2. Apply a thin layer of lithium-based grease or a light oil suited to your application (grease for bearings subject to heavy loads, oil for high-speed bearings).

3. Gently rotate the bearing to distribute the lubrication evenly over the balls and cages.

How to choose a 608 bearing
The choice of 608 bearing depends on the specific application. Here are some criteria to consider:

• Seal type: A 608 2RS or LLB bearing (with rubber seals) is preferable for dusty or damp environments, while a 608 ZZ (with metal shields) is suitable for high-speed applications where moderate protection is sufficient.

• Materials: A steel bearing is suitable for standard applications, while a ceramic bearing is ideal for high-performance applications requiring enhanced corrosion resistance and minimal friction.

• Speed and load: If your application requires very high speeds, opt for a bearing specifically designed for these conditions.