Copper Alloy 770 composition of copper, nickel and zinc results in the metal being a reference as German Silver or Nickel Silver. The metal does contain any silver but will give off a bright silvery appearance.

Comet Metals Inc stocks Copper Alloy 770 in thicknesses from .004 to .100 in. We pride ourselves on fast service, dependability and quality products, at the right price! Rush deliveries, same day shipping on stock items, and overnight delivery are available.

Copper Alloy 770 (55% copper, 27% zinc, and 18% Nickel) can be used in printed circuit board shielding due to its excellent solderability and electricla conductivity.

  • Copper Alloy 752

Comet Metals welcomes any opportunity in Copper Foil,  Copper Coil or sheet products that you may require. Call us at 888-539-5602 today for a quote and learn for yourself  how Comet Metals can assist you in your converter projects. The specifications shown on these pages are not for design purposes.

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Alloy Class:Nickel Silvers
Alloy Name:Nickel Silvers
ASTM Standards:B-122
CDA Number:770
FinishStandard Finishes
Temper:Annealed. (Others Upon Request)
Thickness:0.004 to 0.100 in
Width:Up to 12 in
Copper (Cu):55%
Nickel (Ni): 18%
Oxygen (O2):-
Phosphorus (P):-
Tin (Sn):-
Zinc (Zn):27%
Coefficient of Thermal Expansion: *9.3 Inches/inch/°F x 1,000,000
Density: **0.314 lbs./
Electrical Conductivity: ***5.5 % IACS
Elongation (1/2 Hard):5 to 24
Elongation (1/4 Hard):11 to 41
Elongation (3/4 Hard):3 to 13
Elongation (Annealed): ✦39 to 48
Elongation (Extra Hard):1 to 2
Elongation (Hard):3 to 6
Elongation (Spring):1 (Max)
Hard Elongation (Extra Spring Hard):1 (Max)
Modulus Of Elasticity: ⁑18 x 106 psi
Rockwell (1/2 Hard):71 to 78
Rockwell (1/4 Hard): 63 to 75
Rockwell (3/4 Hard):73 to 78
Rockwell (Annealed): ↠39 to 65
Rockwell (Extra Hard):79 to 82
Rockwell (Extra Spring):81 (Min)
Rockwell (Hard):76 to 80
Rockwell (Spring):80 (Min)
Tensile Strength (1/2 Hard):78 to 95 x 1000 psi
Tensile Strength (1/4 Hard):69 to 87 x 1000 psi
Tensile Strength (3/4 Hard):88 to 101 x 1000 psi
Tensile Strength (Annealed): ✧61 to 76 x 1000 psi
Tensile Strength (Extra Hard):102 to 115 x 1000 psi
Tensile Strength (Extra Spring Hard):116 (Min) x 1000 psi
Tensile Strength (Hard):92 to 107 x 1000 psi
Tensile Strength (Spring):108 to 120 x 1000 psi
Thermal Conductivity: ♦17 BTU/sq.ft./hr/°F
Yield Strength (1/2 Hard):64 to 93 x 1000 psi
Yield Strength (1/4 Hard):44 to 83 x 1000 psi
Yield Strength (3/4 Hard):84 to 100 x 1000 psi
Yield Strength (Annealed): ↡23 to 41 x 1000 psi
Yield Strength (Extra Hard):101 to 114 x 1000 psi
Yield Strength (Extra Spring Hard):115 (Min) x 1000 psi
Yield Strength (Hard):90 to 106 x 1000 psi
Yield Strength (Spring):107 to 118 x 1000 psi
* Inches/inch/°F x 106 from 68°F to 572°F (20°C to 300°C)

** Lbs.per at 68°F (Annealed) ( x 27.68 gms./cu.Cm. at 20°C)

*** % IACS at 68°F (20°C) as annealed

✦ % in 2 inches

⁑ x 106 PSI, tension

↠ 0.020 gauge and above (30T scale)

✧ x 1000 psi

♦ 9.4 BTU per sq.ft.per hr. per °F

↡ 0.2% offset