Manganese Bronze
Metals
Brass
Bronze
DESCRIPTION
CW722R
SPEC SHEET
CW722R is a duplex high tensile brass with a restricted aluminium content to facilitate soldering and brazing. Sometimes referred to as a manganese bronze, CW722R has additions of iron, tin and manganese that benefit the physical and mechanical attributes of the alloy.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 56.50 | 58.50 |
| Pb | 0.80 | 1.60 |
| Al | – | 0.10 |
| Fe | 0.20 | 1.20 |
| Mn | 0.80 | 1.80 |
| Ni | – | 0.30 |
| Sn | 0.20 | 1.00 |
| Total others | – | 0.30 |
| Zn | Remainder | |
Mechanical Properties According To EN12164 CW722R (As Per Temper R440)
| Range (mm) | From | To | UTS Min (N/mm²) | PS Min (N/mm²) | Elongation Min (%) | Hardness Min | Hardness Max |
| Round (Dia) | 40 | 75 | 440 | 200 | 18 | – | – |
| Hex (a/F) | 35 | 60 | 440 | 200 | 18 | – | – |
| Square (A/F) | 35 | 60 | 440 | 200 | 18 | – | – |
| Rectangle (Thickness) | 40 | 50 | 440 | 200 | 18 | – | – |
| PHYSICAL PROPERTIES | |
| Melting Point | 940°C |
| Density 8.42 | g/cm³ |
| Specific Heat | 380 J/Kg°K |
| Thermal conductivity (RT) | 88 W/m°K |
| Thermal expansion coefficient (20-200°C) | 20 x 10-6 |
| Electrical conductivity | 18% IACS |
| Electrical Resistivity | 0.082 ohm mm²/m |
| FABRICATION PROPERTIES | |
| Hot Working Temperature Range | 700-750°C |
| Hot Formability | Very Good |
| Cold Formability | Poor |
| Machinability rating (free cutting brass = 100) | 75% |
| Annealing Temp. Range | 425-600°C |
| Stress Relieving Temp. Range | 225-350°C |
| Soldering | Very Good |
| Brazing | Very Good |
| Oxy-acetylene welding | Not Recommended |
| Gas-shielded arc welding | Not Recommended |
| Resistance welding: Spot and Seam | Not Recommended |
| Butt | Fair |
Typical Uses
- Gas valves and fittings
- Fasteners
- Pump trim
- Gears
- Locks
- Heavy-duty electrical connectors
- Transmission components
- Marine hardware
- Safety tools and decorative metalwork