PTFE Lined DU Bushing

XiaYi PTFE Lined DU Bushing is a composite sliding bearing designed for suspension systems and mechanical joints that require low friction, smooth movement and reduced maintenance. Its three-layer construction combines an alloy steel backing, porous sintered bronze layer and PTFE sliding surface to provide stable support while reducing friction between moving parts.

Unlike conventional metal bushings that often depend on continuous lubrication, the PTFE sliding layer provides self-lubricating performance during repeated movement. This makes the product suitable for shock absorbers, vehicle suspension assemblies and construction machinery operating under frequent reciprocating or oscillating loads.

Product Features

Three-Layer Structure

The alloy steel backing provides mechanical strength and dimensional stability, while the porous sintered bronze layer creates a stable transition between the metal substrate and PTFE sliding surface. The inner PTFE layer forms the main low-friction contact interface with the mating shaft. This composite structure combines structural support, coating adhesion and smooth sliding performance in a compact bushing design.

Main Specifications

Low-Friction Sliding

Friction is an important factor affecting the movement of a bushing. Excessive friction can cause sticking, heat generation, surface wear and inconsistent suspension movement. XiaYi focuses on the sliding interface by combining a PTFE lining with controlled surface finishing to provide smoother movement during repeated mechanical operation.

Self-Lubricating PTFE

The PTFE inner layer creates a low-friction sliding interface between the bushing and mating shaft, reducing dependence on frequent grease application. This characteristic is useful for suspension components and machinery joints where regular lubrication is inconvenient or difficult to perform. Under suitable operating conditions, the self-lubricating surface helps maintain consistent movement while reducing routine maintenance requirements.

Smooth Contact Surface

XiaYi controls the finished surface roughness to Ra≤0.2μm and removes machining burrs during finishing. The smooth contact surface reduces localized friction and helps prevent scratches on the mating shaft. For vehicle suspension systems, this contributes to quieter operation during repeated compression and rebound, while machinery applications can benefit from more stable movement at frequently operating joints.

Wear Resistance

A bushing experiences repeated sliding contact throughout its service life, so wear resistance depends on the PTFE layer, bonding condition, surface preparation and dimensional accuracy. XiaYi combines these factors to maintain a stable sliding interface during long-term operation.

Coating Adhesion

The PTFE composite layer is controlled at 0.02--0.03mm with bonding strength of at least 8MPa. The controlled coating structure helps prevent local peeling and delamination when the bushing is exposed to repeated sliding, vibration and load changes.

Cycle Testing

XiaYi performs wear verification of up to 1 million cycles to evaluate long-term sliding performance. The testing process is used to assess friction stability, coating durability and wear behavior, helping identify potential performance problems before products are supplied for automotive or machinery applications.

Dimensional Fit

The relationship between the bushing, shaft and housing directly affects assembly quality and sliding behavior. Excessive dimensional deviation may create excessive clearance or interference, resulting in uneven contact, accelerated wear or unstable movement.

Key Tolerances

Shaft Compatibility

Before selecting a bushing, buyers should confirm the mating shaft diameter, housing dimensions, axial length, expected load, movement frequency and operating temperature. XIAYI can adjust the bushing dimensions according to customer drawings or samples to achieve the required installation clearance and mechanical fit.

Temperature Performance

Suspension and machinery bushings may experience temperature changes caused by continuous movement, surrounding heat or outdoor operation. Material and coating stability therefore influence long-term sliding performance.

Thermal Curing

XiaYi uses a controlled 180℃±5℃ thermal curing process to stabilize the PTFE composite layer. Controlled curing helps improve the structure of the sliding layer and reduce the possibility of softening or adhesion loss during elevated-temperature operation. The actual working temperature should be evaluated together with load, sliding speed and operating frequency for each application.

Maintenance Needs

The self-lubricating structure is designed to reduce the maintenance work associated with conventional lubricated bushings. This can be particularly useful for vehicle suspension assemblies and outdoor machinery where access to moving joints is limited.

Reduced Lubrication

The PTFE sliding layer can operate without frequent manual grease application under suitable working conditions. Reducing external lubrication can simplify maintenance procedures and help lower the risk of insufficient lubrication during long-term vehicle or equipment operation.

Inspection Requirements

Although frequent lubrication can be reduced, regular inspection remains important for high-load applications. During scheduled maintenance, users can check for excessive clearance, shaft wear, abnormal noise and visible damage to determine whether the bushing or mating components require replacement.

Application Areas

XiaYi PTFE Lined DU Bushing is designed for mechanical assemblies requiring controlled friction, stable sliding and compact structural support. Typical applications include passenger car suspension systems, SUVs, new energy EVs, light and heavy commercial vehicles, excavators, loaders and other construction machinery.

The product can be supplied for OEM assembly, aftermarket replacement and customized mechanical applications where dimensions, load and movement requirements are clearly defined.

Commercial Vehicle Case

In 2025, a domestic commercial vehicle manufacturer replaced the original ordinary bushings with XiaYi PTFE Lined DU Bushing for light truck shock absorber supporting components. The original bushings showed noticeable damping attenuation after approximately 20,000 kilometers, friction noise on uneven roads and occasional coating peeling.

After adopting XiaYi bushings, precision machining improved fitting accuracy, and damping output remained stable after 100,000 kilometers of road testing. The PTFE composite layer and controlled thermal curing process prevented coating delamination during long-term operation, while mirror surface finishing reduced friction-related abnormal noise. CPK≥1.67 process control also improved batch consistency, reducing the after-sales failure rate of the shock absorber bushings by 82%.

Product Comparison

The main difference is the sliding interface. A PTFE-lined design provides a self-lubricating surface with low friction, while a conventional metal bushing generally relies more heavily on lubrication and surface condition to maintain smooth movement.

FAQs

Does it need regular lubrication?

Under suitable operating conditions, frequent manual lubrication is not required because the PTFE layer provides self-lubricating characteristics. Maintenance requirements should still be determined according to load, speed, temperature and operating frequency.

Can it be used in high-temperature applications?

Yes. The product uses a controlled 180℃±5℃ thermal curing process to improve coating stability. For continuous high-temperature applications, the operating temperature, load and sliding speed should be evaluated before final specification selection.

Can the dimensions be customized?

Yes. XIAYI supports customized inner diameter, outer diameter, wall thickness, length and other structural dimensions. Customers can provide drawings, samples or mating component dimensions for specification matching and prototype verification.

What information is needed for product selection?

Buyers should provide the shaft diameter, housing size, bushing length, radial load, movement type, movement frequency, temperature range and installation conditions. These parameters help determine the appropriate bushing dimensions and material configuration.

XIAYI Technical Support

XIAYI focuses on the development and production of precision automotive and mechanical components, including composite sliding bushings for suspension and moving assemblies. Its quality management system is established in accordance with IATF 16949:2016.

For OEM and aftermarket projects, XIAYI can support dimensional matching, sample development, customized production and application-based product selection for passenger vehicles, EVs, commercial vehicles and construction machinery.