Ball bearings: role, types and selection tips

What is a ball bearing?

A ball bearing is a precision mechanical component designed to reduce friction and facilitate rotation between two parts. Used in the majority of industrial and automotive systems, it ensures smooth, reliable and durable movement, even under demanding conditions.

It consists of :

• two rings (inner and outer),

• steel or ceramic balls

• a cage that keeps the balls evenly spaced.

Thanks to this design, it mainly supports radial loads (perpendicular to the axis), but some models are also capable of absorbing axial loads (in the axis).

👉 Most bearings comply with the ISO 15 standard, which defines dimensions. This guarantees perfect compatibility between manufacturers such as SKF, FAG, NSK, NTN or Timken.

Why choose a ball bearing?

The worldwide success of ball bearings can be explained by their many technical and economic 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.

Main types of ball bearings

👉 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 right model, several key parameters need to be taken into account:

• Type of load: radial, axial or combined.

• Standardized dimensions: inside diameter (bore), outside diameter, width.

• Operating conditions: rotation speed, operating temperature, exposure to dust or humidity.

• 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

• bearing 608, known for its use in board sports (skateboarding, rollerblading, scootering), but also in small motors,

• 6201, 6202, 6203, 6204 and 6205 bearings , true mechanical classics, found in household appliances, transmissions and electric motors.

And when operating conditions become more severe - high speeds, polluted environments or low temperatures - NTN-SNR Topline bearings represent an ideal alternative.
Longer-lasting and more reliable than standard ranges, they reduce machine downtime and extend the life of installations.

When applications call for enhanced corrosion resistance, particularly in the food, medical and marine sectors, stainless steel ball bearings are the best solution. Designed to withstand humidity, water splashes and chemicals, they guarantee long-lasting performance where standard bearings quickly reach their limits. Their robustness and reliability make them the preferred choice for all installations where hygiene and longevity are essential.

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?

• 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:

1. internal diameter (bore),

2. outside diameter,

3. width.

These data are engraved on the bearing or can be consulted in manufacturers' catalogs.

Can a ball bearing withstand high speeds?
Yes, some ceramic hybrid bearings reach speeds in excess of 150,000 rpm, notably in electronics, turbines and medical applications.

Order your ball bearings from 123Roulement

With over 50,000 references in stock, 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 filtered by size, type and application,

• fast delivery anywhere in Europe,

• personalized technical support.

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