6912 FHTB1
Manganese bronze contains small additions of manganese, iron, and aluminum, plus lead for lubricity, anti-seizing, and bonding. Like the aluminum bronzes, they combine high strength with excellent corrosion resistance. Manganese bronze bearings can operate at high speeds under heavy loads, but require high shaft hardness and nonabrasive operating conditions
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
|---|---|---|
| Cu | 56.00 | 60.00 |
| Pb | 0.50 | 1.50 |
| Sn | 0.60 | 1.10 |
| Fe | 0.30 | 1.25 |
| Mn | 0.50 | 2.00 |
| Al | - | 0.20 |
| Total Others | - | 0.50 |
| Zn | Remainder | |
Mechanical Properties According To 6912 FHTB1 (As Per Temper HB)
| Range (mm) | From | To | UTS Min (MPa) | UTS Max (MPa) | PS Min (MPa) | Elongation Min (%) | Hardness Min | Hardness Max | |
|---|---|---|---|---|---|---|---|---|---|
| Round (Dia) | 1.5 | 75 | 430 | - | 180 | 15 | - | - | |
| Hex (A/F) | 3 | 70 | 430 | - | 180 | 15 | - | - | |
| Square (A/F) | 3 | 60 | 430 | - | 180 | 15 | - | - | |
| Rectangle | Thickness | 3 | 50 | 430 | - | 180 | 15 | - | - |
| PHYSICAL PROPERTIES | |
|---|---|
| Melting Point - Liquidus°F | 1630 |
| Melting Point - Solidus°F | 1590 |
| Densitylb/cu in. at 68°F | 0.302 |
| Specific Gravity | 8.36 |
| Electrical Conductivity% IACS at 68°F | 24 |
| Thermal ConductivityBtu/ sq ft/ ft hr/ °F at 68°F | 61 |
| Coefficient of Thermal Expansion 68-57210⁻⁶ per °F (68 – 572°F) | 11.8 |
| Specific Heat CapacityBtu/ lb /°F at 68°F | 0.09 |
| Modulus of Elasticity in Tensionksi | 15000 |
| Modulus of Rigidity ksi | 5600 |
| FABRICATION PROPERTIES | |
|---|---|
| Technique | Suitability |
| Soldering | Excellent |
| Brazing | Excellent |
| Oxyacetylene Welding | Good |
| Gas Shielded Arc Welding | Fair |
| Coated Metal Arc Welding | Not Recommended |
| Spot Weld | Good |
| Seam Weld | Fair |
| Butt Weld | Good |
| Capacity for Being Cold Worked | Poor |
| Capacity for Being Hot Formed | Excellent |
| Forgeability Rating | 80 |
| Machinability Rating | 30 |
TYPICAL USES
- Automotive
- Fasteners
- Industrial
- Marine