What are the Available Sizes of Linear Bearings on the Market?

Linear bearings are essential components in many mechanical systems, facilitating smooth, precise linear motion.

The sizes of these bearings can range widely, typically categorized as miniature, standard, and large sizes.

The size of a linear bearing not only influences its load capacity and operating speed but also the specific applications it is suited for.

Manufacturers across the globe produce a vast range of sizes to meet various industrial needs.

This article aims to delve into the available sizes of linear bearings on the market, their applications, and key manufacturers in this field.

What are the Available Sizes of Linear Bearings on the Market

Linear Bearing Sizes:

General Concept of Linear Bearing Sizes

Linear bearings come in a variety of sizes to accommodate different applications and requirements. These sizes usually refer to the inner diameter, outer diameter, and length of the bearing. The sizes can range from a few millimeters for miniature bearings up to several meters for industrial-scale bearings. Understanding the size of linear bearings is critical for engineers and designers in order to ensure smooth operation and a good fit in the intended application.

The Inner Diameter

The inner diameter refers to the inside measurement of the bearing, which is the size of the shaft or rail that the bearing will slide onto. It is one of the most crucial dimensions as it directly affects the fit between the bearing and the shaft or rail.

The Outer Diameter

The outer diameter is the measurement of the outermost edge of the bearing.

The Length

The length of the bearing often refers to the overall distance from one end of the bearing to the other. It influences the load capacity and stability of the bearing.

Factors Determining the Size of Linear Bearings

The size of a linear bearing is determined by several factors, primarily based on its intended application.

Load Capacity

Generally, a larger bearing can support a higher load.

Operating Speed

Bearings used at higher speeds may require larger sizes to accommodate the additional heat generated and to maintain stability.


In corrosive or extreme temperature environments, larger or specialty bearings may be necessary to ensure longevity and performance.

Common Sizing Standards for Linear Bearings

Linear bearing sizes typically follow industry standard sizes, which can make it easier to find and replace bearings in various applications. The two most common standards are metric and inch.

Metric Sizing

Metric sizing is commonly used globally and the sizes are stated in millimeters.

Inch Sizing

In both systems, sizes usually indicate the inner diameter, outer diameter, and length of the bearing.

Detailed Examination of Available Linear Bearing Sizes

Miniature Linear Bearings

Miniature linear bearings are compact, lightweight, and designed for small shafts or rails. Despite their small size, these bearings are capable of handling relatively high loads due to their optimized design.

Key Characteristics

Miniature linear bearings typically have an inner diameter that ranges from 1mm to 10mm.These bearings are particularly common in micro-electromechanical systems (MEMS), miniature robotic systems, and small-scale precision machinery.

Notable Manufacturers

There are several manufacturers known for producing high-quality miniature linear bearings, such as SKF, NSK, and THK.

Standard Size Linear Bearings

They offer a good balance between size, load capacity, and durability, making them a versatile choice for many industries.

Key Characteristics

Standard linear bearings typically have an inner diameter ranging from 10mm to 50mm.

Notable Manufacturers

Well-known manufacturers for standard size linear bearings include Bosch Rexroth, INA, and IKO among others.

Large Size Linear Bearings

Large size linear bearings are designed to handle heavy loads and high impact forces. They are commonly used in heavy machinery and industrial applications where robustness and reliability are crucial.

Key Characteristics

Large linear bearings usually have an inner diameter that is larger than 50mm.

Notable Manufacturers

Prominent manufacturers of large size linear bearings include Timken, NTN Bearing, and Schaeffler.

Applications Based on Linear Bearing Sizes

Usage of Miniature Linear Bearings

These small bearings enable smooth and accurate linear motion for a variety of miniature devices and systems.

Micro-Electromechanical Systems (MEMS)

Miniature linear bearings are essential in MEMS where they allow for precise movement in microscale devices. Examples include micro robots and micro manipulators used in various fields like medicine, research, and technology.

Small Scale Precision Machinery

In industries such as watchmaking, miniature bearings are used in the assembly and maintenance of intricate mechanisms, contributing to the accurate function of timepieces.

Miniature Robotic Systems

These bearings find their applications in miniature robotic systems, facilitating smooth and controlled movement of robotic components.

Usage of Standard Size Linear Bearings

Standard size linear bearings find wide application across numerous industries due to their versatility in handling different loads and speeds.

CNC Machines

In CNC machines, standard size linear bearings enable precise and smooth movement of the machine parts, leading to high-precision machining of components.

3D Printers

In 3D printers, these bearings facilitate accurate movement of the extruder, thus aiding in producing detailed and intricate 3D models.

Usage of Large Size Linear Bearings

Large size linear bearings are often found in heavy-duty applications where high load capacity and impact resistance are required.

Construction Equipment

Large size linear bearings are vital components in construction machinery such as excavators and cranes, ensuring the smooth movement of heavy parts.

Heavy Transport Systems

In heavy transport systems, these bearings provide the necessary linear movement to facilitate the transport of heavy goods, contributing to the efficiency of transport operations.

Industrial Machinery

In various types of industrial machinery, large linear bearings ensure smooth movement of heavy machine parts, contributing to the overall efficiency and productivity of the industrial operations.

Key Manufacturers and Their Offerings

Leading Manufacturers of Linear Bearings

There are several key players in the manufacturing of linear bearings worldwide.


SKF’s product line includes a wide range of linear bearings suitable for various applications, including those requiring miniature, standard, and large sizes.



Japanese manufacturer NSK is another industry leader in bearing production. They offer a broad selection of linear bearings, designed for durability and performance across different industries.


They produce a wide variety of linear bearings, including unique designs that offer high precision and load capacities.

Size Varieties Offered by Different Manufacturers

Different manufacturers offer a variety of sizes to cater to diverse applications, ensuring there is a suitable bearing for virtually any requirement.

SKF’s Offering

SKF offers a comprehensive range of sizes, from miniature bearings with an inner diameter of 1mm to large industrial bearings with diameters over 50mm.

NSK’s Offering

NSK also provides a wide range of bearing sizes. They produce miniature linear bearings starting at 3mm inner diameter and go up to larger sizes for heavy-duty applications.

THK’s Offering

THK specializes in offering an extensive range of sizes. Their products include compact bearings suitable for precision applications and larger bearings designed to handle high loads in heavy machinery.

Considerations when Selecting Linear Bearing Sizes

Load Capacity

Load capacity is a crucial factor when selecting the size of a linear bearing. The chosen bearing must be able to support the anticipated load of the application to ensure longevity and efficient operation.

Static Load Capacity

The static load capacity refers to the maximum load that a linear bearing can handle without movement.

Dynamic Load Capacity

The dynamic load capacity is the maximum load a bearing can handle while in motion.

Installation Space

It’s essential to measure the dimensions of the installation space accurately to ensure the chosen bearing fits perfectly.

Housing Space

Consider the dimensions of the housing or mounting surface where the bearing will be installed.

Shaft or Rail Size

The size of the shaft or rail that the bearing will slide onto must also be factored into the bearing size selection.

Shaft or Rail Size

Environmental Conditions

The operating environment significantly affects the selection of linear bearing sizes. Certain conditions may require larger or specially designed bearings to ensure performance and longevity.


In extreme temperature environments, larger bearings may be needed to accommodate thermal expansion and improve heat dissipation.

Corrosive Environment

In corrosive environments, specific materials and bearing sizes may be required to resist corrosion and maintain performance.

Speed and Precision Requirements

The required operating speed and precision of the application play a role in determining the suitable size of the linear bearing.

High-Speed Applications

For high-speed applications, larger bearings may be required to handle the increased heat generated and ensure stability.

Precision Applications

A perfectly fitted bearing can minimize play and enhance the precision of the application.


  1. Linear Bearing – Wikipedia
  2. SKF – Wikipedia
  3. NSK – Wikipedia
  4. THK – Wikipedia
  5. Micro-Electromechanical Systems – Wikipedia
  6. CNC Machines – Wikipedia
  7. 3D Printing – Wikipedia

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