Copper brazing alloy used mainly to join carbide to steel. Offers high strength and economy compared to silver brazing alloys.

#773 is a high temperature, high strength corrosion resistant copper brazing alloy that is primarily used for the joining of steel to steel or carbide to steel. Due to the high flow point, we recommend the use of Black Flux. Because of the zinc content, it is recommended that the heat cycle is kept to a minimum to prevent any vaporizing of the zinc. #773 is often commonly referred to as a Nickel Silver alloy


Material Nickel-Silver
Melting Pt. 1690 ºF 921 ºC
Flow Pt. 1715 ºF 935 ºC
MBT 1800
MIL R-19631
Federal Specification QQ-B-650
Preform Options Brazing Discs Brazing Rings Brazing Spheres Custom Design Cutoffs
Resale Options Brazing Paste Brazing Rod Brazing wire Spooled Brazing Material
Approx. Wire Length (BCuP/lb.) (BAg/Tr.oz) 1097 in; 0.062 diameter 4475 in; 0.031 diameter 487 in; 0.093 diameter

Physical Constants

Solidus 1690 ºF 921 ºC
Liquidus 1715 ºF 935 ºC
Recommended Braze Temperature 1740 ºF
Specific Gravity 8.47
Density 0.296 lb./cu.in
Electrical Conductivity 5.5 % IACS
Electrical Resistivity 31.4 Micro ohm-cm
Color Light Yellow


A high temperature, high strength copper brazing alloy well suited for carbide to steel applications.


Download SDS Sheet

Bellman-Melcor distinguishes itself as a provider of premium quality brazing alloys at industry competitive prices. Our extensive inventory of brazing and soldering alloys ensures that in most cases your order can be available for immediate delivery.

Compare With

  • AWS: RBCuZn-D
  • UNS: C77300


  • Brazing Temperature Range High: 1815 F / 991 C
  • Brazing Temperature Range Low: 1765 F / 963 C
  • Liquidus: 1715 F / 935 C
  • Solidus: 1690 F / 921 C



  • Cu: 48%
  • Zn: 41.885%
  • Ni: 10%
  • Si: 0.145%

The information and recommendations contained in this publication have been provided without charge & compiled from sources believed to be reliable and to represent the best information available on the subject at the time of issue. No warranty, guarantee, or representation is made by the Prince and Izant Company, Inc. as to the absolute correctness or sufficiency of any representation contained in this and other publications; Prince and Izant Company, Inc. assumes no responsibility in connection therewith; nor can it be assumed that all acceptable safety measures are contained in this and other publications, or that other or additional measures may not be required under particular or exceptional conditions or circumstances. The company and product names referenced herein are for identification purposes only. All trademarks and registered trademarks are the property of their respective owners.

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