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C905
Tin Bronze / Gun Metal (905)
C90500
Overview
C90500 is a tin bronze (gun metal) alloy known for its good strength, excellent wear resistance, and outstanding corrosion resistance to steam, water, and dilute acids. With 10% tin content, it provides superior bearing properties compared to lower-tin alloys. C905 is widely used for valve bodies, pump casings, piston rings, and marine fittings where reliable performance in corrosive environments is essential.
Chemical Composition
| Element | Min | Max |
|---|---|---|
| Copper (Cu) | 86.00% | 89.00% |
| Tin (Sn) | 9.00% | 11.00% |
| Zinc (Zn) | 1.00% | 3.00% |
Alloy Designations
UNSC90500
ASTMB505, B584
Common NameGun Metal / Tin Bronze
Mechanical Properties
Tensile Strength40 ksi (276 MPa) min
Yield Strength18 ksi (124 MPa) min
Elongation20% min
Hardness70 HB typical
Physical Properties
Density8.77 g/cm³ (0.317 lb/in³)
Melting Point850–1,000°C (1,562–1,832°F)
Electrical Conductivity11% IACS
Thermal Conductivity74.8 W/m·K
Typical Applications
- Valve bodies and valve seats
- Pump casings and impellers
- Piston rings
- Marine fittings and hardware
- Steam fittings
- Bearings for moderate loads
Fabrication & Joining
- Good machinability
- Soldering: Excellent
- Brazing: Good
- Weldability: Fair
- Excellent corrosion resistance to steam and water