Linear bearings are the backbone of precise, repeatable motion in modern automation. Whether you are designing a pick-and-place system in Melbourne, a conveyor in Brisbane, or a CNC machine in Perth, selecting the right linear bearing type determines the accuracy, longevity, and uptime of your machine.

This guide covers the principal types of linear bearings used in industrial automation, how to choose between them, and what Australian engineers and machine builders should look for when specifying or sourcing components locally.

1,000+Linear bushing variants    –    80+Countries served by Bosch Rexroth    –    24/7Breakdown support    

What are linear bearings?

A linear bearing is a mechanical element that enables smooth, constrained motion along a straight axis. Unlike rotary bearings, which support rotating shafts, linear bearings guide a carriage, block, or bushing along a fixed rail or shaft — with minimum friction and maximum positional accuracy.

In automation, linear bearings appear in virtually every machine that moves: robotic arms, gantry systems, laser cutters, packaging equipment, semiconductor handlers, and battery cell assembly lines. The bearing type chosen directly affects load capacity, speed, rigidity, maintenance intervals, and total cost of ownership.

Types of linear bearings used in automation

There are four main families of linear bearing technology in widespread use across Australian manufacturing and automation. Each suits a different range of applications, load requirements, and environmental conditions.

Profiled rail (ball rail)

Recirculating ball elements in a precision-ground runner block on a hardened rail. Excellent balance of speed, accuracy, load capacity, and cost.

Profiled rail (roller rail)

Cylindrical rollers replace balls for significantly higher rigidity, load capacity, and moment resistance. Preferred for heavy machine tools.

Linear bushing & round shaft

A recirculating ball bushing running on a precision round shaft. Cost-effective for light-to-medium loads in less demanding environments.

Linear motion systems

Pre-engineered modules combining guidance, drive, and structure. Ball screw or toothed belt driven, ready-to-install, minimal design effort.

Ball rail vs roller rail: which should you choose?

The most common specification decision for precision automation is the choice between a ball rail system and a roller rail system. The table below summarises the key differences.

Characteristic Ball rail system Roller rail system
Rolling element Recirculating balls Cylindrical rollers
Load capacity High Very high
Rigidity / stiffness High Significantly higher
Moment resistance Good Superior
Maximum speed Higher Moderate
Noise level Lower Slightly higher
Typical applications Assembly automation, pick-and-place, CNC axes, semiconductor Heavy machine tools, large machining centres, pressing
Relative cost Lower Higher

 

For most automation applications, including pick-and-place, robotic handling, assembly, and standard CNC axes,  a ball rail system such as the Bosch Rexroth BSHP or BSCL provides the optimal balance. Where extreme rigidity and maximum moment loads are the priority, roller rail systems are the engineering solution of choice.

Linear bushings and round shaft systems

Where budget is a primary constraint, or where loads are modest and the environment is relatively controlled, linear bushings on precision round shafts remain a proven and widely used solution. The Bosch Rexroth linear bushing range includes over 1,000 variants covering standard (LB), Super Series, torque-resistant (LBTR), and compact configurations.

When to specify a linear bushing
Round shaft systems are well suited to pick-and-place jigs, light assembly fixtures, medical equipment, laboratory automation, and applications where the carriage span is short and loads are well within the bushing’s rated capacity. For heavier loads, longer strokes, or applications requiring high accuracy under varying load directions, a profiled rail system will deliver better long-term performance.

Accuracy classes explained

Bosch Rexroth profiled rail systems are manufactured in multiple accuracy classes, ranging from normal (N) through high (H), precision (P), and super precision (SP). Accuracy class governs the height and width tolerances of the runner block as fitted to the rail — which directly determines the positional accuracy of the machine axis.

For general automation and assembly, normal or high accuracy classes are typically sufficient. CNC machining centres, semiconductor equipment, and medical instrumentation often require precision or super precision grades. Specifying a higher accuracy class than your application requires adds unnecessary cost; under-specifying can compromise machine performance and product quality.

The Linear Technik technical team can assist with accuracy class selection based on your positional tolerance requirements and loading conditions.

Sealing, lubrication, and contamination resistance

Linear bearing service life is heavily influenced by correct sealing and lubrication. Bosch Rexroth profiled rail systems are available with end seals, side seals, and scraper plates to exclude contamination — essential in environments where metal swarf, coolant, dust, or food particles are present.

Integrated lubrication systems, including oil-hole nipples and grease nipple connections compatible with central lubrication systems, are standard features across the Rexroth range. For applications in food processing, pharmaceutical manufacturing, or washdown environments, Resist CR variants in corrosion-resistant stainless steel materials are available.

Ready-to-install linear motion systems

For machine builders seeking to reduce design effort and commissioning time, Bosch Rexroth linear modules, compact modules, and Omega modules combine guidance, drive, and structural elements into pre-engineered, pre-assembled systems. These are particularly valuable for:

Linear modules

Ball rail guidance with ball screw or toothed belt drive. Fast integration, reliable positioning, compact envelope.

Omega modules

Toothed belt drive for travel speeds up to 5.0 m/s. Ideal for high-speed handling and rapid traverse axes.

Cartesian systems

Multi-axis gantry and handling solutions. Pre-configured with cable management and control hardware.

Industries using linear bearings in Australia

Linear bearings are specified across a broad range of Australian industries. Common applications Linear Technik supplies and supports include:

Industry Typical linear bearing application Recommended bearing type
CNC machining Machine tool axis guidance and ball screw feed drives BSHP ball rail or roller rail + ball screw
Industrial automation Pick-and-place, palletising, assembly BSCL ball rail or linear modules
Semiconductor & electronics Ultra-precise positioning, wafer handling Miniature ball rail, high accuracy class
Battery & EV manufacturing Cell assembly, welding, handling Ball rail systems, linear modules
Medical & laboratory Sample handling, imaging, dispensing Miniature ball rail, linear bushings
Food & packaging Conveying, filling, labelling Resist CR corrosion-resistant variants
Materials handling Conveyor integration, gantry systems Linear modules, aluminium profile systems

Frequently asked questions

Are Bosch Rexroth linear bearings interchangeable with other brands?
Bosch Rexroth profiled rail systems are designed to be interchangeable within their own product range — rails and runner blocks of the same size and accuracy class can be combined freely. They are not designed to be interchangeable with other manufacturers’ products. Contact Linear Technik if you are upgrading or replacing components from a mixed-brand system.
What is the difference between preload classes in a ball rail system?
Preload is the internal force applied between the rolling elements and the raceways, eliminating play and increasing rigidity. Higher preload classes give greater rigidity and moment stiffness but increase running friction. The correct preload class depends on your stiffness requirements and the nature of the applied loads.
Can I get linear bearing components cut to length or machined locally in Australia?
Yes. Linear Technik’s onsite workshop in Australia can cut profiled rail to length, drill and tap rails for fixing, machine ball screws, and cut and assemble aluminium profile frame systems. This eliminates the need for import lead times on machined components.
What is the Bosch Rexroth Integrated Measuring System (IMS)?
The IMS is a magnetic position measurement system fully integrated into the Rexroth runner block. It provides accuracy comparable to glass scales but with far greater resistance to contamination, vibration, and shock — removing the need for a separate external encoder or scale in many applications.
Does Linear Technik supply linear bearings to customers outside Melbourne?
Yes. Linear Technik supplies Bosch Rexroth linear motion components and systems to customers across all Australian states and territories, including Sydney, Brisbane, Perth, Adelaide, and regional locations. Same-day dispatch is available for in-stock items.
What if my machine breaks down outside business hours?
Linear Technik operates a 24/7 Breakdown Service to help you source critical linear motion components urgently and minimise unplanned downtime. Contact us any time.

Need help selecting a linear bearing for your application?

The Linear Technik technical team can assist with product selection, load calculations, accuracy class guidance, and sourcing — for both planned projects and urgent breakdown requirements, anywhere in Australia.

CONTACT OUR TEAM