Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

Thin Section Bearings

we will provide a comprehensive overview of thin section bearings, including their design, materials, applications, and maintenance. We will also discuss the advantages and disadvantages of thin section bearings and how to select the right bearing for your application.

Design of Thin Section Bearings

Thin section bearings are designed to have a much smaller cross-sectional profile than traditional bearings. This design allows for a higher radial load capacity and increased precision in applications where space is at a premium. Thin section bearings are also known as "slim bearings" or "thin-walled bearings."

The design of thin section bearings consists of four main components: inner and outer rings, balls or rollers, and a cage. The inner and outer rings are made from steel or other high-strength materials and are designed to withstand high radial and axial loads. The balls or rollers are also made from high-strength materials and are designed to rotate freely within the bearing.

The cage is the component that holds the balls or rollers in place and prevents them from contacting each other. The cage is typically made from steel or other materials that are resistant to wear and corrosion. The design of the cage can also affect the performance of the bearing, as it can affect the distribution of the load and the speed of the bearing.

Materials Used in Thin Section Bearings

Thin section bearings are made from a variety of materials, depending on the application and the desired performance characteristics. The most common materials used in thin section bearings are steel, stainless steel, and ceramic.

52100 Chrome Steel is the most common material used in thin section bearings because of its strength and durability. However, steel bearings are susceptible to corrosion and wear over time, especially in harsh environments.

Stainless steel bearings are another popular option for thin section bearings. Stainless steel is resistant to corrosion and wear and is often used in applications where the bearing is exposed to moisture or chemicals.

Ceramic bearings are a newer type of thin section bearing that offers several advantages over traditional steel bearings. Ceramic bearings are lighter, stronger, and more resistant to wear and corrosion than steel bearings. They also offer better performance at high speeds and temperatures, making them ideal for applications in aerospace and other high-performance industries.


Angular Contact Thin Section Bearings (Type A): In applications with high axial loads, Type-A angular contact thin section ball bearings should be used. The thin section bearings also work well in radial or combined radial-thrust applications. The Type-A thin section bearings should never be used alone to support moment loads or reversing axial loading. Two Type-A thin bearings are often used as a duplex pair.

Four Point Contact Thin Section Bearings (Type X):The Type-X thin section bearings, or the 4-point contact thin wall ball bearings are ideal for moment loading. Type-X ultra thin section bearings are designed with gothic arch raceways creating 4 contact points between the balls and the raceways. This design is excellent for moment loading and reversing axial loading. The Type-X thin section bearings can be used for other light loading conditions, but is not recommended in place of the Type-C or Type-A thin section bearings for pure radial loads.

Radial Contact Thin Section Bearings (Type C):The Type-C thin section wall bearings, that is, the radial contact thin section bearings, is designed with deep ball grooves to withstand high loads. Although this bearing is used primarily in applications with radial loads, it can withstand moderate axial loads, reversing axial loads, and moment loads.


AUB has manufactured thin section bearings from SAE 440C stainless steel to provide corrosion resistance. As an alternative to stainless steel rings, the entire surface of the rings can be plated with nodular thin dense chrome (TDC). This plating, which meets AMS 2438, achieves a molecular bond that will not flake, peel or separate from the base material. The TDC plate has a hardness of HRC 70 - 78 and can withstand temperatures well beyond the range of the base material.

Special thin section bearings have been manufactured from Aluminum, 300 Series Stainless Steel, 17-4 Stainless Steel, and other metals.


Some special ball materials available include 440C Stainless Steel, 300 Series Stainless Steel, Silicon Nitride and M-50 Steel.

Precision: ABEC-1 to ABEC-7

Thin section bearings are available in four precision grades. ABEC grades 1, 3, 5 and 7 respectively. The tolerances for the bearing bores, outer diameters and radial plays are shown in the products tables.


Thin section bearings range in bore diameters from 0.750 inch to 40.000 inches. Product line range from .187 x .187 inch to 1.000 x 1.000 inch in cross section.

Seal Type

Open type thin section bearings: Oil lubricated, with low starting torque and flexible rotation.

Sealed thin section bearings: Consist of nitrile/BUNA-N rubber bonded to a metal washer. High temperature PTFE seals (up to 250°C) or Viton seals (up to 230°C) are available on some sizes. The inner lip of the seal rubs against the bearing inner ring to provide an effective seal against smaller particles such as dust and moisture while preventing lubricant leakage. Contact seals produce much higher frictional torque levels than open bearings and reduce the maximum speed of a bearing. Below -40°C nitrile rubber and viton will stiffen and provide a less effective seal so PTFE seals or metal shields should be considered for very low temperatures.

Construction: constant section, deep groove

The cross-section remains constant even in the case of larger shaft and housing bore diameters, therefore the thin section bearings are also described as constant section (CS) bearings. There are three configurations of thin section bearings. They are angular contact thin section bearings (Type A), Conrad assembled deep groove radial thin section ball bearings (Type C), and four-point contact radial thin section bearings (Type X).

Thin section Bearings with the deep groove ball bearing structure are available in open type bearings, shield (2Z) or seals (2RS).

System of Measurement

System of thin section bearings include Inch system and Metric system.


Cage materials of thin section bearings cover brass, nylon, phenolic and stainless steel.


Many different lubricants are available from AUB Bearing for special applications. Greases which are designed specifically for high speed, low torque, water resistance, high temperature, oscillatory motion and food machinery can be provided. Additional lubricants, such as dry film, are suitable for use in vacuums and space applications. For more details, please refer to the website of Ball Bearing Lubrication.


Thin section bearings with Normal chrome steel can be used at constant temperatures of 120°C or intermittent temperatures of up to 150°C. Above these temperatures, the load capacity of the chrome steel will be reduced. By means of special heat treatment processes and the addition of high temperature grease, we can also customize thin section bearings for high temperature resistance.

Internal Clearance

Internal clearance is the play between outer ring, inner ring and rolling element of thin section bearings. Generally, the amount of up and down movement of the outer ring with respect to the fixed inner ring is called the radial internal clearance and its right and left movement the axial internal clearance. Bearing internal clearance in operation is an important factor that has a significant influence on other factors such as noise, vibration, heat and fatigue life.

Applications of Thin Section Bearings

Thin section bearings are used in a variety of applications where space is at a premium, and high precision is required. Some of the most common applications of thin section bearings include robotics, aerospace, medical equipment, and industrial machinery.

  • In robotics, thin section bearings are used in the joints and moving parts of the robot. These bearings are designed to withstand high radial and axial loads while maintaining precise movement and positioning.
  • In aerospace, thin section bearings are used in a variety of applications, including flight control systems, landing gear, and engines. These bearings are designed to withstand extreme temperatures and pressures while maintaining high levels of precision and reliability.
  • In medical equipment, thin section bearings are used in imaging equipment, surgical tools, and other critical applications. These bearings are designed to be lightweight, precise, and durable, making them ideal for use in sensitive medical equipment.
  • In industrial machinery, thin section bearings are used in a variety of applications, including conveyors, pumps, and motors. These bearings are designed to withstand high loads and speeds while maintaining high levels of precision and reliability.

Advantages of  Thin Section Bearings

Thin section bearings offer several advantages over other types of bearings, including reduced weight, increased precision, and improved speed.

1. Reduced weight: Because of their smaller size and thin cross-section, thin section bearings are lighter than other types of bearings. This is particularly important for applications where weight is a limiting factor, such as aerospace or robotics.

2. Smaller size: Thin section bearings can be designed to have very small dimensions, enabling them to fit into tight spaces and provide high precision even in limited areas.

3. High precision: Due to their design, thin section bearings can provide very accurate positioning and rotational functions. They are ideal for applications that require precision and accuracy, such as surgical instruments, robotics, and high-precision machinery.

4. Reduced friction: Thin section bearings are designed to have a low coefficient of friction, reducing energy losses and minimizing wear. This results in longer service life and reduced maintenance requirements.

5. Durable: Thin section bearings are made using high-quality materials, such as chrome steel or stainless steel. This makes them more resilient to damage and ensures that they can withstand high loads and extreme environments.

Overall, thin section bearings are a great choice for applications that require high precision, reduced weight, and long service life.