C521 Bronze Alloy Wire (CuSn8)

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Alloy C521 is a high tin alloy of the phosphor bronze family. The additional tin relative to the more commonly used C510 results in higher mechanical properties with a modest reduction in electrical conductivity. Applications include electronic parts, springs, contacts, switch parts and fasteners.

Mechanical Properties

Round Wire

Temper Name  Temper Code  Tensile Strength (N/mm²) Mill Limits 
Min Max
Annealed   365 470 .0254 - 3.264 mm
1/4 Hard H01 510 625
1/2 Hard H02 655 795
3/4 Hard H03 780 930
Hard H04 860 1035

Square Wire

Temper Name  Temper Code  Tensile Strength (N/mm²) Mill Limits 
Min Max
Annealed   365 470 .2540 - 1.905 mm
1/4 Hard H01 510 625
1/2 Hard H02 655 795
3/4 Hard H03 780 930
Hard H04 860 1035

Rolled Flat

Temper Name  Temper Code  Tensile Strength (N/mm²) Mill Limits 
Min Max
Annealed   365 460

Thickness:
.2540 - 1.905 mm

Width:
.3810 - 6.350 mm

1/2 Half Hard H02 475 580
Hard H04 585 690
Extra Hard H06 670 770
Spring H08 725 820
Extra Spring H10 760 840

Physical Properties

Melting Point (Liquidis) 1027°C
Melting Point (Solidus) 882°C
Density 8.80232 gm/cu cm
Electrical Resistivity (Annealed) 13.2662 ?? -cm @ 20°C
Electrical Conductivity (Annealed) 0.0761 MegaSiemens /cm @ 20°C
Thermal Conductivity (Solutionized-Aged) 62.33684211 W/m · °K @ 20°C
Coefficient of Thermal Expansion 0.00001818°C (20-300°C)
Modulus of Elasticity (Tension) 110300 MPa
Modulus of Rigidity 41400 MPa