| Alloy name | C7351 | C7451 | C7521 | C7701 | PMC1240 |
| Characteristics | Silver color / Work-hardening Alloy / Good Chemical Corrosion Resistance | ||||
| Applications | Transistor Cap | Transistor Cap | Transistor Cap | Connector / Switch / Relay |
Key Blank |
| Alloy name | C7351 | C7451 | C7521 | C7701 | PMC1240 | ||
| Chemical Composition (wt%) | Cu | 70-75 | 63-67 | 62-66 | 54-58 | Balance | |
| Zn | Balance | Balance | Balance | Balance | 35-42 | ||
| Ni | 16.5-19.5 | 8.5-11.0 | 16.5-19.5 | 16.5-19.5 | 9.0-13.0 | ||
| Mn | 0-0.5 | 0-0.5 | 0-0.5 | 0-0.5 | - | ||
| Pb | ≤0.03 | ≤0.03 | ≤0.03 | ≤0.03 | - | ||
| Fe | ≤0.25 | ≤0.25 | ≤0.25 | ≤0.25 | - | ||
| Physical Properties | Melting Temp. (℃) | 1135 | 1021 | 1110 | 1054 | 1054 | |
| Specific Gravity | 8.8 | 8.86 | 8.75 | 8.7 | 8.7 | ||
| Thermal Conductivity {W/(m·K)} |
36 | 45 | 33 | 29 | 29 | ||
| Coefficient of Thermal Expansion(10-6/K) |
16.0 | 16.4 | 16.2 | 16.7 | 16.7 | ||
| Modulus of Elasticity in Tension(kN/mm²) |
124 | 121 | 124 | 124 | 124 | ||
| Poisson's Ratio | 0.33 | 0.34 | 0.32 | 0.32 | 0.33 | ||
| Electrical Conductivity (%IACS) |
6.5 | 9.0 | 6.0 | 5.5 | 5.5 | ||
| Mechanical Properties |
Tensile Strength (N/㎟) |
O | ≥325 | ≥325 | ≥375 | - | - |
| 1/2H | 390-510 | 390-510 | 440-570 | 540-655 | - | ||
| H | - | - | 540-640 | 630-735 | 588-686 | ||
| EH | - | - | ≥610 | 705-805 | - | ||
| SH | - | - | - | 765-865 | - | ||
| Elongation (%) |
O | ≥20 | ≥20 | ≥20 | - | - | |
| 1/2H | ≥5 | ≥5 | ≥5 | ≥11 | - | ||
| H | - | - | ≥3 | ≥6 | ≥8 | ||
| EH | - | - | - | ≥4 | - | ||
| SH | - | - | - | - | - | ||
| Hardness (Hv) |
O | - | - | - | - | - | |
| 1/2H | 105-155 | 105-155 | 120-180 | 150-210 | - | ||
| H | - | - | 150-205 | 180-240 | 190-210 | ||
| EH | - | - | ≥185 | 210-260 | - | ||
| SH | - | - | - | 230-270 | - | ||
