Wear Resistant DU Bushing with Stable Guide Performance
Model DP-4 | Brand XIAYI | Certification IATF16949:2016
The DP-4 DU bushing features a tri-layer composite structure — low-carbon steel backing, sintered bronze interlayer, and a PTFE-based anti-friction running surface. Designed for heavy-load, maintenance-free applications, this self-lubricating bushing eliminates the need for external grease or oil systems while delivering consistent low-friction performance from -195oC to +280oC.
Structure & Material Composition
| Layer | Material | Function |
| Surface Layer (0.01-0.03mm) | PTFE + Fibre Compound | Self-lubricating anti-friction surface, forms protective transfer film on mating shaft |
| Interlayer (0.20-0.35mm) | Sintered Porous Bronze | Thermal conductor, lubricant reservoir, mechanical bond between steel and PTFE |
| Backing | Low-Carbon Steel | High load capacity, dimensional stability, heat dissipation |
| Plating | Copper / Tin (0.002mm) | Corrosion protection for steel backing |
Technical Specifications
| Parameter | Value |
| Model | DP-4 / SF-1D |
| Operating Temperature Range | -195oC to +280oC |
| Load Capacity (Static) | Up to 250 N/mm² |
| Load Capacity (Dynamic) | Up to 140 N/mm² |
| Max Sliding Speed (Dry) | 2.5 m/s |
| Coefficient of Friction (Dry) | 0.04 - 0.20 |
| Surface Layer Thickness | 0.01 - 0.03 mm |
| Shaft Tolerance Recommendation | h7 - h9 |
| Housing Tolerance Recommendation | H7 |
| Shape Options | Cylindrical, Flanged, Thrust Washer |
Key Advantages
- Maintenance-Free Operation: PTFE surface layer eliminates the need for periodic grease or oil lubrication, reducing total cost of ownership in hard-to-access installations.
- Wide Temperature Range: Functional from cryogenic (-195oC) to high-temperature (+280oC) environments, suitable for both freezer equipment and heated industrial processes.
- Self-Lubricating Transfer Film: During initial run-in, a microscopic PTFE film transfers to the mating shaft surface, creating a low-friction interface that protects both components from wear.
- Thin-Wall Design: Compact cross-section reduces housing size and weight compared to traditional bronze bushings, supporting equipment miniaturization.
- Low Noise Operation: The polymer-based running surface absorbs vibration and eliminates metal-on-metal contact noise.
Real-World Engineering Challenges & DP-4 Solutions
"Our cement conveyor bushings fail every 3 months due to abrasive dust ingress and lack of lubrication access."
The DP-4's PTFE surface operates without external lubrication and forms a self-renewing transfer film. Its sintered bronze interlayer acts as a secondary lubricant reservoir, providing a built-in safety margin even when surface abrasion occurs.
"The heat from continuous casting machines causes standard bushings to seize after a few production cycles."
With an upper operating limit of 280oC, the DP-4 maintains dimensional stability and friction performance well above the thermal threshold of greased bronze bushings. The steel backing efficiently conducts heat away from the friction interface.
"We need bushings that work in food-grade environments where external lubricants are prohibited."
DP-4 bushings operate completely dry with no external lubrication required. The PTFE compound is chemically inert and does not contaminate product contact surfaces, making it suitable for food processing, pharmaceutical, and clean-room equipment.
"High static loads during machine startup cause brinelling damage to conventional bearings."
The DP-4's composite structure handles static loads up to 250 N/mm² without permanent deformation. The steel backing provides the compressive strength to resist brinelling, while the PTFE layer ensures immediate low-friction sliding as soon as movement begins.
Manufacturing Capability
Processing Equipment
CNC Machining Center
CNC Turning
CNC Milling
4-Axis Machine
CNC Drilling
Auto Lathe
Surface Finishing
Anodizing
Powder Coating
Zinc Plating
Copper Plating
Tin Plating
Laser Engraving
Application Industries
- Steel metallurgy — continuous casting machine roller grooves, mill guides
- Cement & construction — grout pumps, screw conveyors, mixing equipment
- Heavy vehicles — suspension pivot points, kingpin bushings, spring shackles
- Agricultural machinery — harvester linkages, tiller pivot assemblies
- Industrial automation — robotic arm joints, conveyor roller bearings
- Marine & offshore — deck equipment, hatch cover rollers, mooring systems
Frequently Asked Questions
Q: What is the minimum order quantity for DP-4 bushings?
Standard MOQ is 500 pieces. For prototype or sample evaluation, smaller quantities are available. Please contact our sales team with your dimensional requirements.
Q: Can you supply DP-4 bushings in custom dimensions?
Yes. XIAYI offers full customization of inner diameter, outer diameter, length, and flange dimensions. Thrust washers in custom sizes are also available. Provide your technical drawing for a feasibility assessment and quotation.
Q: What plating options are available for corrosion protection?
Standard options include copper plating, tin plating, and zinc plating. For marine or highly corrosive environments, we can discuss specialized coatings. Contact our engineering team with your environmental requirements.
Q: How do DP-4 bushings compare to traditional bronze bushings in terms of service life?
In dry-running or marginally lubricated applications, DP-4 bushings typically outlast bronze bushings by 3-10 times due to the PTFE self-lubrication mechanism. The transfer film continuously protects both the bushing and the mating shaft, whereas bronze relies on external lubrication that degrades over time.
Q: What is the delivery time for standard orders?
Standard delivery is approximately 2 weeks from payment receipt. Production capacity exceeds 50,000 pieces per month, ensuring reliable supply for volume orders.
Q: Can the DP-4 be used in submerged or wet environments?
Yes. The PTFE surface is hydrophobic and chemically stable in water, mild acids, and alkalis. For fully submerged applications, we recommend tin-plated backing for enhanced corrosion protection. The bushing performs equally well in wet conditions as in dry.