ZQSn6-6-3 Oilless Bearing
ZQSn6-6-3 Oilless Bearing
ZQSn6-6-3 Graphite Self-Lubricating Bronze Bushing: The Cost-Effective Wear Solution for Hydraulic Valves & Pumps
In high-pressure hydraulic systems, component failure is not an option. The ZQSn6-6-3 graphite-impregnated oilless bronze bushing is engineered to deliver exceptional reliability and wear resistance in moderate-load hydraulic applications. By embedding solid graphite lubricant into a durable tin-bronze alloy base, this bushing provides continuous, maintenance-free lubrication, reducing downtime and operational costs for critical components like hydraulic valves and pumps.
Key Benefits for Your Application
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Maintenance-Free Operation: Solid graphite plugs provide consistent self-lubrication, eliminating the need for external grease or oil and preventing contamination in hydraulic fluids.
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Cost-Effective Performance: Delivers excellent wear resistance and durability for moderate-load conditions at a more economical price point compared to high-performance aluminum bronzes.
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Superior Wear Resistance: The tin-bronze alloy (ZCuSn5Pb5Zn5 equivalent) base offers high load-bearing capacity and excellent anti-friction properties, extending the service life of your equipment.
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Excellent Machinability: This alloy is easily machined to precise tolerances, allowing for custom-fit bushings that meet your exact design specifications.
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Anti-Seizure Properties: The composition is inherently resistant to galling and seizure, ensuring smooth, reliable operation even under intermittent or boundary lubrication conditions.
Technical Specifications: ZQSn6-6-3 (ZCuSn5Pb5Zn5)
This material, also known by its current standard grade ZCuSn5Pb5Zn5, provides a balanced profile of mechanical properties ideal for a wide range of industrial uses.
| Property | Value Range | Benefit in Hydraulic Systems |
| Tensile Strength | 180 – 220 MPa | Provides sufficient strength for moderate-pressure components. |
| Hardness | ≥68 HB | Ensures excellent resistance to surface wear and deformation. |
| Friction Coefficient | ~0.09 (Dry) | Lowers operational friction, reducing heat and energy loss. |
| Specific Gravity | 8.82 g/cm³ | Indicates a dense, robust material structure. |
| Thermal Conductivity | 0.22 C.G.S | Helps dissipate heat generated from friction during operation. |
| Solid Lubricant | Embedded Graphite Plugs | Guarantees continuous self-lubrication throughout the part’s life. |
Material Selection Guide: ZQSn6-6-3 vs. ZQAL9-4
Choosing the right material is critical for performance and budget. Use this table to compare our cost-effective ZQSn6-6-3 tin bronze with the high-performance ZQAL9-4 aluminum bronze.
| Feature / Parameter | ZQSn6-6-3 (Tin Bronze) | ZQAL9-4 (Aluminum Bronze) | Selection Guideline |
| Primary Application | Moderate load, consistent speed hydraulic systems. | High load, high-impact, and shock-load applications. | Match the material to your system’s operational intensity. |
| Load Capacity | Moderate | High to Very High | Choose ZQAL9-4 for heavy-duty cylinders, construction equipment, and high-pressure pumps. |
| Shock Resistance | Good | Excellent | ZQAL9-4 is superior for applications with frequent starts/stops, pressure spikes, or impacts. |
| Cost-Effectiveness | Excellent | Good | ZQSn6-6-3 offers the best price-to-performance ratio for standard hydraulic applications. |
| Wear Resistance | Very Good (Excellent anti-seizure) | Excellent (Superior hardness and strength) | Both are durable, but ZQAL9-4 excels under extreme abrasive or high-pressure conditions. |
| Ideal Application | Spool valve sleeves, gear pump bushings, cylinder guide rings. | Trunnion bearings, heavy-duty piston rod guides, pivot pins. | Use this as a starting point to identify the best fit for your specific component. |
Specific Application Parts in Hydraulic Systems
Our ZQSn6-6-3 bushings are precision-engineered for critical locations within hydraulic machinery, including:
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Hydraulic Pumps: Bushings for gear pumps, vane pumps, and piston pumps where consistent, moderate loads are present.
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Hydraulic Valves: Sleeves and guide bushings for directional control valves, spool valves, and pressure relief valves.
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Hydraulic Cylinders: Guide bushings for piston rods and cylinder glands in standard-duty applications.
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Actuators & Motors: Linkage and pivot point bearings requiring reliable, low-friction movement.
Frequently Asked Questions (FAQ)
Q1: What makes the ZQSn6-6-3 bushing “oilless” or “self-lubricating”?
A: The bushing’s base bronze material is machined with pockets that are then filled with solid graphite plugs. During operation, a thin film of graphite is transferred to the mating shaft, creating a continuous, dry lubricating layer that eliminates the need for grease or oil.
Q2: When should I choose ZQSn6-6-3 instead of a higher-strength bronze like ZQAL9-4?
A: Choose ZQSn6-6-3 when your application involves moderate loads and speeds without significant shock or impact forces. It is the ideal, cost-effective choice for general-purpose hydraulic systems where reliability and low maintenance are key priorities. If your system experiences high impacts or extreme loads, ZQAL9-4 would be a better fit.
Q3: Is ZQSn6-6-3 the same as ZCuSn5Pb5Zn5?
A: Yes. ZQSn6-6-3 is the legacy grade designation under the former GB 1176-74 standard. The chemically equivalent and currently recognized grade under the GB/T 1176-1987 standard is ZCuSn5Pb5Zn5. We manufacture to the modern standard to ensure consistent quality.
Q4: Can Bearingface.com provide custom sizes for these bushings?
A: Absolutely. We specialize in manufacturing custom-dimensioned bushings, flanged bearings, and thrust washers based on your technical drawings or specifications. Contact our engineering team to discuss your custom requirements.
Ready to Improve Your Hydraulic System’s Reliability?
Contact our engineering team today for a free consultation or request a no-obligation quote for your ZQSn6-6-3 self-lubricating bushing needs.
