Sintered Bronze Bushing: High-Performance Self-Lubricating Bearing Solution
May 05, 2025
Core Advantages and Application Value of Sintered Bronze Bushing
Sintered bronze bushing is a porous self-lubricating bearing manufactured by powder metallurgy technology, known as "maintenance-free bearing" in the industrial field. The global market size is expected to reach US$1.87 billion in 2025, with an annual growth rate of 6.2%. Its unique structure brings five core advantages:
✅ Self-lubricating properties: oil content 15-25% (no need to refuel for a long time)
✅ High temperature resistance: working range -40℃ to +250℃
✅ Shock absorption and noise reduction: pore structure absorbs vibration (noise reduction of 30dB)
✅ High load capacity: static load up to 140N/mm²
✅ Economical and durable: life span is 3-5 times that of ordinary bushings
Four major classification systems of sintered bronze bushings
1. Classification by material composition
CuSn10 (10% tin bronze): general purpose, best cost performance
CuSn6Zn6Pb3: contains zinc and lead, good cutting performance
CuFe2.5: high thermal conductivity, suitable for high temperature environment
CuNi15Zn20 (German silver): corrosion-resistant special alloy
2. Classification by structural design
Standard cylindrical bushing (ISO 3547)
Flange bushing (with axial positioning edge)
Spherical bushing (±15° self-aligning)
Special-shaped custom bushing (for chain links/guide rails)
3. Classification by lubrication method
Pre-lubricated type (impregnated with mineral oil/synthetic oil)
Compound lubrication type (PTFE/graphite inlay)
Relubrication type (with oil injection hole design)
4. Classification by accuracy level
| Level | Inner diameter tolerance | Applicable scenarios |
| P0 level | ±0.05mm | Precision instruments |
| P6 level | ±0.1mm | General machinery |
| P8 level | ±0.2mm | Agricultural equipment |
Typical application scenarios and selection guide
🛠️ Industrial field
Injection molding machine: template slide rail (recommended CuSn10+PTFE)
Automobile: Steering system (DIN 1494 certification required)
Food machinery: Use FDA-certified lead-free formula
⚙️ Special environment
Vacuum equipment: special low-volatile oil impregnation
Seawater environment: CuNi15Zn20 alloy
High-speed rotation: Contains MoS₂ solid lubricant
📐 Selection calculation formula
PV value verification:
P (pressure N/mm²) × V (speed m/s) ≤ material limit PV value
*Example: For power tool applications (P=2N/mm², V=1m/s), bushings with PV≥2 must be selected*
Production process of sintered bronze bushings
Raw material ratio: copper powder (88-92%) + tin powder (8-12%) + lubricant
Pressure molding: 300-800MPa cold isostatic pressing
Sintering: 780-850℃ protective atmosphere (H₂/N₂)
Finishing: CNC lathe correction size (Ra0.8μm)
Oil impregnation: vacuum impregnation (ISO VG68~220 engine oil)
Installation and maintenance specifications of sintered bronze bushings
🔧 Installation points
Press fit: interference 0.02-0.05mm
No hammering (special installation tools required)
Align oil hole with lubrication pipeline (if applicable)
🛠️Maintenance recommendations
Check oil content every 2000h (oil film area ≥ 80%)
Abnormal wear judgment criteria:
Inner diameter expansion > 0.1mm
Surface peeling or cracking
Relubrication cycle:
Standard type: 8000 working hours
Heavy load type: 3000 working hours
Industry certification and quality assurance
International certification: ISO 5753, ASTM B438
Automotive standard: SAE J459
Warranty period: 24 months (normal use conditions)
Test report: SGS material analysis can be provided
Frequently Asked Questions (FAQ)
❓ What is the difference with graphite copper sleeves?
✅ Sintered bronze has oil in the base, while graphite copper sleeve has a composite graphite layer on the surface. The former is more suitable for intermittent motion
❓ How to calculate the maximum speed?
📐 Formula: Nmax = (PV value × 19100) / (P × D)
(N = speed rpm, D = inner diameter mm)
❓ How to solve the abnormal noise?
Check whether it is lack of oil (replenish the same type of lubricant)
Eliminate shaft eccentricity (radial runout ≤ 0.03mm)
Replace with an upgraded model with PTFE
❓ Can it replace ball bearings?
⚠️ Only recommended in:
Low speed and heavy load (<1m/s)
Dust environment
Occasions where shock absorption is required
