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C932
Bearing Bronze (SAE 660)
C93200 (SAE 660)
Overview
C93200 (SAE 660) is the workhorse bearing bronze alloy, widely used across industrial bearing applications. This leaded tin bronze offers excellent lubricity from its lead content, good machinability (70 rating), and reliable performance under moderate loads and speeds. SAE 660 is the most commonly specified bearing bronze for bushings, thrust washers, and general-purpose bearing applications. It is available in continuous cast solid bar, tube, rectangle, and near-net shapes.
Chemical Composition
| Element | Min | Max |
|---|---|---|
| Copper (Cu) | 81.00% | 85.00% |
| Tin (Sn) | 6.30% | 7.50% |
| Lead (Pb) | 6.00% | 8.00% |
| Zinc (Zn) | 2.00% | 4.00% |
| Iron (Fe) | — | 0.20% |
| Nickel (Ni) | — | 1.00% |
Alloy Designations
UNSC93200
SAE660
ASTMB505/B505M
FederalQQ-C-390, Comp E7
MilitaryMIL-B-11553, Comp 12
Mechanical Properties
Tensile Strength35 ksi (241 MPa) min
Yield Strength (0.5% ext.)20 ksi (138 MPa) min
Elongation10% min
Brinell Hardness65 HB typical
Machinability Rating70
Physical Properties
Density8.91 g/cm³ (0.322 lb/in³)
Melting Point (Liquidus)977°C (1,790°F)
Melting Point (Solidus)854°C (1,570°F)
Electrical Conductivity12% IACS
Thermal Conductivity58.2 W/m·K
Modulus of Elasticity100 GPa (14,500 ksi)
Typical Applications
- General-purpose bushings and bearings
- Diesel engine wrist pin bushings
- Hydraulic press linings
- Rolling mill bearings
- Pump impellers and fixtures
- Thrust washers
- Forging press toggle lever bearings
- Automotive fittings
Fabrication & Joining
- Continuous cast — solid, tube, rectangle
- Soldering: Excellent
- Brazing: Good (strain must be avoided during brazing)
- Oxyacetylene welding: Not recommended
- Gas shielded arc welding: Not recommended
- Machinability: 70 rating