Ball bearings: role, types and selection tips

What is a ball bearing?

A ball bearing is a system consisting of two rings (one inner and one outer), a cage and steel or ceramic balls within the cage.

They are designed to reduce friction and facilitate movement and rotation between two different parts. Ball bearings can be found absolutely everywhere: in everyday objects (bicycle wheels, washing machines), in motor vehicles, but also in cutting-edge industrial installations such as turbines or wind turbines.

It can be adapted to a wide range of situations and conditions, from high speeds and temperatures to demanding sanitary conditions.

Thanks to its design, it can be used to support radial loads (perpendicular to the axis) as well as axial loads (in the axis), and is made to absorb shocks.

These bearings are governed by the ISO 15 standard, which in particular defines their dimensions. Manufacturers must therefore ensure compatibility between them, such as SKF, FAG, NSK, NTN or Timken.

Why are ball bearings essential?

A ball bearing fulfills a role that no other mechanical part can, and offers numerous advantages:

• Versatility: suitable for a wide variety of applications (industrial, automotive, agricultural, household appliances).

• Low friction: their design limits energy losses and enables rotation speeds of over 100,000 rpm for certain ceramic models.

• Durability: manufactured in special steels, stainless steels or ceramics, some bearings boast a service life of several million hours when properly maintained.

• Wide range: single- or double-row bearings, 2RS or ZZ seals, high-temperature bearings, ceramic hybrids... there's a solution for every application.

The main types of ball bearings

123Roulement offers you different types of ball bearings:

• Single row: the most standard version found on our skateboards and bicycle wheels, but also in various types of motors or transmission machines, they are economical and versatile.

• Double-row: offers a higher radial load capacity than the single-row version, and is found in agricultural and automotive machinery.

• Ball joint: designed to compensate for shaft misalignment. It has a long shaft and is used for assemblies requiring flexibility.

• Thrust ball bearings: generally made of steel, they are used in many industrial machines.
  Ball thrust bearings are designed exclusively to support axial loads (in the axis) and are not resistant to radial loads. They are mainly used for light to moderate loads.
  There are two different types of thrust bearing: single-acting and double-acting.
  They are easy to install and maintain.

• Ceramic bearings: There are two types of ceramic bearing: the full-ceramic type, in which all bearing components are made of ceramic, and the hybrid type, in which only the balls are made of this material.
  They are designed for applications where electrical insulation and high speeds are required.
  Ceramic bearings offer advantages such as low friction, high precision and resistance to wear and corrosion.

• High-temperature bearings: designed to withstand high-heat environments, these bearings can operate in environments ranging from 180°C to 330°C, whereas a standard bearing generally does not exceed 120°C. They are therefore essential for demanding sectors.
  These bearings are used in the steel, ceramics and paper industries, as well as for overhead conveyors and industrial fans.
  High-temperature bearings are generally 6000 6200 or 6300 series bearings.

• Ball-bearing roller: designed to facilitate linear or rotary movement while supporting loads. There are again two types of roller: single-row and double-row.
  They combine various advantages such as high load capacity, increased precision and stability, and low friction.

👉 These different variants make it possible to adapt the bearing to the specific constraints of each sector: load, speed, temperature or environment.

How to choose the right ball bearing?

To select the ball bearing you really need, you need to take into account a number of factors, not just the bearing itself, but also the environment in which it will be used.

To select the right model, you need to consider several key parameters:

• Load: will it be radial, axial or both? Depending on the load, you'll be more likely to choose a thrust bearing for an axial load, or a double-row ball bearing for a radial load.

• Standardized dimensions: inside diameter (bore), outside diameter, width. Bearings are available with a wide range of these dimensions.
  For small dimensions, 608 bearings (8 x 22 x 7 mm) are widely used, especially in skateboarding and rollerblading. conversely, for industrial or automotive applications requiring sturdier parts, models such as 6010 or 6210 bearings, with bores up to 50 mm, are preferred.

• Operating constraints and environment: The choice of bearing depends on the conditions in which it will be used and the need it meets.
  The speed of rotation required, the operating temperature or exposure to dust and humidity are determining factors in the choice of your ball bearing.
  Choosing the right bearing will influence its performance and service life.

• sealing:

  • Z → metal flange on one side only.

    ZZ → metal flanges on both sides, better suited to dry, clean environments.

    RS, LU, DU, RSR → rubber seal on one side only.

    2RS, LLU, DDU, 2HRS → rubber seals on both sides for enhanced protection against water and dust.

    💡 Expert tip: to prolong the life of your bearings, ensure regular lubrication and use greases suited to the conditions (high speed, high heat, humid environment).

Essential references and specialized ranges

In addition to the major ball bearing families, certain models stand out for their almost universal presence in a wide range of equipment. These so-called "standard" references are often the first thing our customers look for, as they equip both industrial machines and everyday applications.

They include :

• The 608 bearing , whose standardized dimensions and quality/price ratio make it the most popular ball bearing. It is used in a wide range of applications, from skateboard wheels to industrial machines and electric motors. The 608 ball bearing is available in a wide range of brands and with different types of seals, radial clearances or cages.

• Bearings 6201, 6202, 6203, 6204 or 6205 are true classics. They can be found in household appliances (washing machines, vacuum cleaners), electric motors and transmission systems. Their versatility and reliability make them the safe choice for a wide range of applications.

• Stainless steel bearings: in environments exposed to humidity, corrosion or sanitary constraints (food processing, medical, pharmaceutical industries), stainless steel bearings are the preferred choice.
  They offer excellent resistance to rust, while maintaining high performance.

• NTN-SNR Topline specialized ranges. When conditions become more severe - high speeds, polluted environments or low temperatures - NTN-SNR Topline bearings are the ideal alternative.
  Longer-lasting and more reliable than standard ranges, NTN-SNR Topline ball bearings reduce machine downtime and extend the life of plant and equipment.

  ---

  FAQ - All you need to know about ball bearings

  What is the service life of a ball bearing?
  Depending on load, speed and lubrication, a bearing can last from a few thousand hours to several million. Under ideal conditions, its service life can exceed 100,000 operating hours.

  What's the difference between a 2RS and a ZZ bearing?

  The difference lies in the material of the sealing elements:

  • A 2RS bearing has two rubber seals, ideal for dusty or damp environments.

  • A ZZ bearing has two metal flanges, offering light protection but suitable for dry environments.

  How do I measure a bearing for replacement?
  Three measurements are essential:

  • internal diameter (bore),

  • outside diameter,

  • width.

  These data are often engraved directly on the bearing and available in manufacturers' catalogs.

  ---

  Order your ball bearings from 123Roulement

  123Roulement is the ball bearing specialist. Whether you're a professional or a private customer, we offer you :

  • a wide range of well-known brands: SKF, FAG, NSK, NTN, Timken...

  • a catalog that can be filtered by size, type and application,

  • fast delivery,

  • personalized technical support at all times.

  Find the ideal ball bearing in just a few clicks on 123Bearing.com and guarantee the reliability of your machines at the best price.