When it comes to selecting the right bushing material for demanding mechanical applications, engineers and procurement professionals often compare various types based on load-bearing capacity, friction performance, temperature tolerance, and maintenance requirements. Among the most widely used bushing types are SF-1, SF-2, and graphite plugged bronze bushings. Each has unique characteristics suited for specific environments, from dry, high-load conditions to oil-lubricated, high-temperature operations.
Understanding Bushing Material Types
SF-1 Bearing Material
SF-1 bearing material is a type of dry self-lubricating bearing constructed with a composite structure. It typically features a steel backing for strength, a porous bronze sintered layer, and a PTFE-based anti-friction layer. This combination delivers excellent low-friction performance and wear resistance without the need for lubrication, making it ideal for dry working conditions.
Key advantages of SF-1:
SF-2 Bronze Bushing
The SF-2 bronze bushing, in contrast, is designed for marginally lubricated environments. It features a bronze base with embedded solid lubricants in the form of micro-indentations or lubricant reservoirs. This construction offers a balance between the robustness of bronze and the enhanced lubrication offered by oil or grease.
Main benefits:
What Is a Graphite Plugged Bronze Bushing?
The graphite plugged bronze bushing—also referred to as a self-lubricating graphite bearing—is a solid bronze bushing that has been embedded with graphite plugs. These plugs serve as permanent lubricants and offer exceptional performance in extreme conditions, including high temperatures, heavy loads, and environments where lubrication is difficult or impossible.
Typical features:
Load and Friction Comparison
| Bushing Type | Lubrication Type | Load Capacity | Friction Coefficient | Temperature Resistance |
| SF-1 | Dry | High | Very Low (Dry) | -195°C to +280°C |
| SF-2 | Marginal Oil | Medium | Low (With Oil) | -40°C to +250°C |
| Graphite Bronze | Self-Lubricating | Very High | Low (Self-Lubricated) | Up to +400°C |
Dry Bearing vs Oil Bearing
Understanding the difference between dry bearings and oil bearings is crucial. Dry bearings, like SF-1, function without external lubricants, relying on built-in low-friction surfaces. They are suitable for clean, maintenance-free applications. On the other hand, oil bearings, like SF-2, require occasional lubrication but offer longer life under continuous motion or heavier loads when properly maintained.
Bronze Bushing for High Temperature Applications
Among the three types, graphite plugged bronze bushings are the preferred bronze bushings for high temperature environments. Their ability to withstand temperatures up to 400°C, combined with their self-lubricating properties, makes them ideal for furnaces, steel mills, and heavy-duty industrial applications.
Choosing the Right Supplier
Finding a reliable self-lubricating bushing supplier in China is essential to ensure product quality, consistency, and cost-effectiveness. As a leading bush manufacturer in China, ZJB offers a wide range of SF-1, SF-2, and graphite bronze bushings tailored to different industrial requirements, with customization available based on load, size, and working environment.
Conclusion
Each bushing material—SF-1, SF-2, and graphite plugged bronze—has its strengths depending on your application needs. Whether you require low-friction dry operation, moderate lubrication with bronze strength, or extreme durability in high-load and high-temperature settings, there's a solution that fits. Understanding the load and friction performance of each type helps engineers make informed choices and optimize the reliability and longevity of their machinery.
