C86300 (SAE 430B)
Manganese Bronze
Manganese Bronzes
Highest strength of standard copper alloys, excellent wear resistance. Used for heavy-duty bearing and structural applications.
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| Copper (Cu) | 60 | 66 |
| Zinc (Zn) | 22 | 28 |
| Iron (Fe) | 2 | 4 |
| Aluminum (Al) | 3 | 7.5 |
| Manganese (Mn) | 2.5 | 5 |
Physical Properties
| Density | 0.284 lb/cu in |
|---|---|
| Specific Gravity | 7.86 |
| Melting Point (Solidus) | 1583°F |
| Melting Point (Liquidus) | 1625°F |
| Electrical Conductivity | 8% IACS |
Mechanical Properties
| Tensile Strength | 110–119 ksi |
|---|---|
| Yield Strength | 60–67 ksi |
| Elongation | 14–18% |
| Hardness | 223–240 BHN |
| Machinability Rating | 8 |
Thermal Properties
| Thermal Conductivity | 21 Btu/ft·hr·°F |
|---|---|
| Coefficient of Expansion | 11.5 × 10⁻⁶ /°F |
| Specific Heat | 0.09 Btu/lb·°F |
Fabrication Properties
Typical Applications
- Slow-speed, heavy-load bearings
- Bushings
- Gears
- High-strength machine parts
- Screw-down nuts
- Bridge pins
- Cams
- Frames
- Gib
- Hooks
- Hydraulic cylinder parts
- Large valve stems
- Struts
- Brackets
- Electrical components
- Switches
- Forming dies for the wood pulp industry
- Wear rings for forming dies for the wood pulp industry
- Propellers
- Rudders
- Boat parts
- Marine hardware
- Covers for marine hardware
- Clamps
Design & Selection
C86300 (SAE 430B) is the high-strength manganese bronze. The Copper Development Association's use list selects it for slow-speed, heavy-load bearings, screw-down nuts, gears, and bridge pins, where strength and wear resistance govern. It also carries salt-water corrosion resistance, which is why it appears in propellers, rudders, and marine hardware. Its low machinability rating makes it a deliberate choice for the high-load end of the range rather than a general-purpose bearing stock.
Specification Cross-Reference
| UNS | C86300 |
|---|---|
| Former SAE designation | SAE 430B |
| ASTM — centrifugal castings | B271 |
| ASTM — continuous castings | B505 |
| ASTM — sand castings (general) | B584 |
| ASTM — valve sand castings | B763 |
| ASTM — bridge and turntable castings | B22 |
| ASTM — ingot | B30 |
| SAE | J461, J462 |
| AMS | AMS 4862 |
| Military / Federal | QQ-C-523, MIL-C-11866 |
Specification and applications data per the Copper Development Association (copper.org).
Frequently Asked Questions
Common questions about C86300 Manganese Bronze specifications and applications.
C86300 Manganese Bronze is commonly used for bridge trunnions, gears and cam rollers, large bearings, and hydraulic cylinder parts, marine propellers. Highest strength of standard copper alloys, excellent wear resistance. Used for heavy-duty bearing and structural applications.
C86300 has a machinability rating of 8 (on a scale where free-cutting brass C36000 = 100). This indicates lower machinability, requiring specialized tooling and slower cutting speeds.
C86300 has a tensile strength range of 110-119 ksi. This high strength makes it suitable for heavy-duty structural and load-bearing applications.
Yes, C86300 offers good corrosion resistance. It performs well in various industrial environments.
C86300 is a cast alloy. It is available through sand casting, centrifugal casting, and continuous casting processes.