Round Linear Shafting

Round linear shafting typically uses GCr15 bearing steel as the raw material. Chrome-plated rods made from this material exhibit excellent mechanical strength and wear resistance. After undergoing a carburizing and quenching process, the surface hardness of the steel is significantly enhanced, effectively meeting the required surface hardness standards and extending service life.

A circular linear bearing is a linear motion system designed to work with a cylindrical shaft for unlimited stroke. Because the load-carrying balls make point contact with the bearing's outer sleeve, the linear bearing maintains low friction and stable motion regardless of speed, enabling sensitive, smooth, and high-precision linear movement.

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Applications

• Industrial Machinery: Commonly used in sliding components of precision machine tools, textile machinery, food packaging machinery, and printing machinery.
• Precision Equipment: Applied in computers and peripherals, measuring instruments, automatic recorders, and 3D measuring devices.
• Specialized Equipment: Suitable for multi-axis drilling machines, punching machines, tool grinders, automatic gas cutting machines, printers, card sorters, and packaging machines.

Key Characteristics

• Low noise, low friction, and high precision
• Long service life with enhanced wear resistance
• Stable motion unaffected by speed variations
• Smooth and accurate linear movement due to point contact between balls and shaft

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1. Core Features of Round Linear Shafting

Compact Structural Design

The flange of the round linear shafting is integrated with the bearing, effectively reducing radial space requirements - particularly suitable for installation spaces under 20 mm.
The circular flange can be directly fixed with bolts, simplifying the assembly process and ensuring precise alignment.

Core Structural Composition

Round linear shafting adopts a modular design, mainly consisting of three core components:

• Bearing Seat

Serves as the supporting body, typically made of aluminum alloy or cast iron. It offers high strength and wear resistance, providing a stable installation reference for the entire unit.

• Linear Bearing

The key moving part that achieves low-friction linear motion through rolling steel balls or rollers along the guide shaft, with precision reaching micron-level accuracy.

• End Caps

Installed at both ends of the bearing, they provide dust-proof sealing and stroke-limiting functions, effectively preventing contamination and ensuring smooth travel.

High Precision & Low Friction

The steel balls roll in point contact with the hardened shaft, maintaining a friction coefficient of less than 0.005.
This design enables micron-level repeat positioning accuracy (±0.1 μm), ensuring smooth and stable motion without crawling.

High Load Capacity & Vibration Resistance

The multi-row steel ball configuration evenly distributes axial and radial loads (e.g., LM30UU radial load up to 1.8 kN).
An aluminum alloy retainer absorbs vibration and shock, improving stability under high-speed operation.

Environmental Resistance & Long Service Life

Manufactured from bearing steel (SUJ2) or treated with hard chrome plating, the shaft offers outstanding wear and corrosion resistance.
A dust-proof sealing ring extends the lubrication cycle, providing a service life of over 5000 km under normal conditions.

Flexible Adaptability

Available in multiple structural variants to meet diverse application needs:

• Standard type (LM series)
• Open type (adjustable clearance)
• Extended type (LME series)

Applicable for shaft diameters ranging from φ4 mm to φ50 mm.

2. Typical Application Scenarios

Precision Industrial Fields

• Automation Equipment

Linear feed of CNC tool holders, nozzle positioning of 3D printers.

• Testing Instruments

Translation mechanisms for optical platforms, probe guidance in coordinate measuring machines.

• Semiconductor Manufacturing

Wafer transfer robot joints requiring high cleanliness and nanometer-level motion stability.

Dynamic Control Systems

• Industrial Robots

Guidance for welding or assembly robotic arm end-effectors, capable of high-frequency reciprocating motion.

• Packaging Machinery

Film deviation correction systems and vertical lifting mechanisms for filling valves, often paired with air cylinders.

Special Environment Applications

• Medical Equipment

Slides for CT scanner beds and surgical robot arms, designed for low-noise, sterile environments.

• Food Production Lines

SUS440C stainless steel bearings for conveyor guidance in beverage and filling lines, offering water and corrosion resistance.

• Transportation and Vehicle Systems

Logistics Sorting Lines: Guide shafts for roller conveyors with intermittent impact loads.

Automotive Components: Seat adjustment slides and battery module positioning pins in electric vehicles.

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• Product Name

Round Linear Shafting

• Material

GCr15 bearing steel

• Specifications

Length can be precisely cut and customized according to customer requirements.
Various diameters and surface treatments are available upon request.

Product Advantages

• High Hardness

Heat-treated through professional carburizing and quenching processes, providing outstanding surface hardness and mechanical strength.

• Rust & Corrosion Resistance

Advanced chrome plating and surface treatment technology enhance rust protection, suitable for various industrial environments.

• Precision Grinding

Manufactured using precision grinding to ensure tight dimensional tolerances and superior surface finish.

• Wear Resistance & Durability

Excellent combination of hardness, toughness, and corrosion resistance ensures extended service life even under continuous operation.

Customized Packaging Options

• Reinforced Wooden Case - Crashproof, pressure-resistant, ideal for export sea transportation.
• Vacuum Anti-Rust Packaging - Suitable for long-term storage or humid environments.
• Custom Branding - Customer logo printing and batch-specific packaging available.

Delivery Cycle

Sample Orders: 3–7 working days

Bulk Orders: 7–30 working days (depending on quantity and logistics conditions)

Performance Testing Standards

1. Clearance Inspection

The bearing clearance is measured using a feeler gauge to ensure it falls within the specified tolerance range.
Proper clearance is an essential prerequisite for ensuring stable operation, smooth motion, and extended service life of the bearing.

2. Noise Detection

During rotation, dynamic auscultation is performed to identify any abnormal sounds.
High-quality linear bearings should maintain smooth, stable operation without noticeable noise, vibration, or irregular acoustic feedback.

3. Straightness and Surface Roughness Detection

• Straightness of Round Linear Shafting

The straightness deviation must be controlled within 50 μm per 300 mm (i.e., the shaft should not deviate more than 50 microns for every 300 mm of length).

• Surface Roughness of Round Linear Shafting

The surface finish should meet the Ra0.2–Ra0.4 μm standard, ensuring high contact accuracy, minimal friction, and excellent wear resistance.

Round linear shafting are precision-engineered components, requiring extra care during installation. Please observe the following key points when assembling linear motion accessories:

• Standardized Operation - Avoid Impact

Handle all components carefully to prevent accidental detachment or damage.

Do not strike any accessories directly with hammers or hard tools. Strong impact may cause precision deviation, bearing deformation, or performance degradation.

• Accurate Verification of Installation Dimensions

Before installation, verify the dimensional accuracy of the housing, shaft, and guide rail mounting surfaces.

Ensure that dimensional tolerances and fit precision meet technical specifications to prevent misalignment or operational jamming caused by dimensional errors.

• Thorough Removal of External Impurities

Foreign materials such as metal debris, dust, or chips can enter the linear shaft system, leading to wear or malfunction.

Clean the installation area thoroughly before assembly. Use dust-free cloths or specialized cleaning agents to remove all contaminants and residues.

Lubrication Requirements

Round linear shafting without lubrication will experience increased friction loss and shortened lifespan. Proper lubrication should be performed as follows:

• Lubricant Selection: Use turbine oil compliant with ISO VG 32–68 or NLGI Grade 2 lithium-based grease.
• Lubrication Cycle: Replenish lubricant periodically based on operational frequency to maintain a complete oil film on the rolling contact surface.

Dust Protection Measures

In dust-prone or harsh working environments, additional protection is required:

• Environmental Protection: Install dust covers, sealing strips, or protective bellows to prevent metal debris or dust from entering the motion components.
• Special Environment Maintenance:

For equipment exposed to high humidity, corrosive gases, or chemical vapors, use composite lubricants that combine rust prevention and dust protection. Strengthen the sealing design to ensure long-term reliability.

DLY has established a one-stop service ecosystem covering pre-sales consultation, in-sales tracking, and after-sales support, aiming to become your trusted partner in precision manufacturing.

Pre-Sales: Precise Demand Matching

• Technical Consultation:

A team of engineers with over 10 years of industry experience provides free model selection and technical guidance. We recommend optimal models based on load conditions, precision requirements, and installation constraints.

• Customized Solutions:

Support for non-standard customization, including 3D model design, load simulation, and performance verification to accelerate customers' R&D and design cycles.

In-Sales: Full-Process Transparency

• Order Tracking:

A dedicated account manager provides real-time updates at every production stage - from raw material inspection to machining, quality testing, and final packaging.

• Logistics Optimization:

Intelligent logistics matching ensures on-time delivery via domestic special lines or international sea/air freight, with real-time tracking codes provided.

After-Sales: Long-Term Assurance Mechanism

• Warranty Service:

All standard products include a 1-year extended warranty, covering free replacement for material or manufacturing defects.

• Quick Response:

24/7 after-sales hotline available - inquiries responded to within 1 hour, and complete solutions provided within 24 hours.

• Lifetime Maintenance:

Cost-price maintenance beyond warranty period, with regular customer follow-ups to collect operational feedback and continuously enhance product performance.

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