CW724R
CW724R, a type of silicon red brass, is specifically chosen for use in underground service lines due to its exceptional corrosion resistance when exposed to various potable waters. This alloy also possesses moderate strength and retains good spring properties over time.
Silicon brasses, including CW724R, belong to the high-strength brass subgroup. They are characterized by containing less than 20% zinc and less than 6% silicon. These brasses achieve their high strength through solid solution strengthening. They are commonly selected for applications requiring both high strength and reasonably high corrosion resistance, making them an ideal choice for underground service lines.
CHEMICAL COMPOSITION
| Elements | Min (%) | Max (%) |
| Cu | 75.00 | 77.00 |
| Pb | – | 0.10 |
| Fe | – | 0.30 |
| Sn | – | 0.30 |
| Ni | – | 0.20 |
| Mn | – | 0.05 |
| Al | – | 0.05 |
| P | 0.02 | 0.10 |
| Si | 2.70 | 3.50 |
| Total Others | – | 0.15 |
| Zn | Remainder | |
MECHANICAL PROPERTIES ACCORDING TO CW724R EN12164 (AS PER TEMPER R500)
| Range (mm) | From | To | UTS Min (MPa) | PS Min (MPa) | Elongation Min (%) | Hardness Min | Hardness Max |
| Round (Dia) | 35 | 75 | 500 | 450 | 15 | – | – |
| Hex (A/F) | 35 | 70 | 500 | 450 | 15 | – | – |
| Square (A/F) | 35 | 60 | 500 | 450 | 15 | – | – |
| Rectangle (Thickness) | 35 | 50 | 500 | 450 | 15 | – | – |
| PHYSICAL PROPERTIES | |
| Melting Point – Liquidus°F | 1685 |
| Melting Point – Solidus°F | 1510 |
| Density lb/cu in. at 68°F | 0.26 |
| Specific Gravity | 8.19 |
| Electrical Conductivity % IACS at 68°F | 6.2 |
| Thermal Conductivity Btu/ sq ft/ ft hr/ °F at 68°F | 15 |
| Coefficient of Thermal Expansion 68-57210⁻⁶ per °F (68 – 572°F) | 11.2 |
| Specific Heat Capacity Btu/ lb /°F at 68°F | 0.09 |
| Modulus of Elasticity in Tension ksi | 16000 |
| FABRICATION PROPERTIES | |
| Technique | Suitability |
| Soldering | Excellent |
| Brazing | Excellent |
| Oxyacetylene Welding | Good |
| Spot Weld | Good |
| Seam Weld | Good |
| Butt Weld | Good |
| Capacity for Being Cold Worked | Good |
| Capacity for Being Hot Formed | Excellent |
| Forgeability Rating | 80 |
| Machinability Rating | 80 |
