Also known as low-fuming bronze, this alloy provides versatility without the higher cost of silver brazing alloys. Works best for induction or torch brazing. Excellent results on ferrous and non-ferrous base metals.

#681 is a versatile copper brazing alloy suited for the joining of steel, copper, copper alloys, nickel, nickel based alloys, and stainless steel where corrosion resistance is not a major requirement. This copper brazing alloy has gained popularity as an economical alternative to silver brazing alloys.

Most commonly brazed via torch or induction, it is best to keep the heat cycle to a minimum to prevent vaporizing the zinc. Flux is required when brazing with #681.


Material Low Fuming Bronze
Melting Pt. 1590 ºF
866 ºC
Flow Pt. 1630 ºF
888 ºC
MBT 1750
MIL R-19631
Federal Specification QQ-B-571a
ASTM B 259
Preform Options Brazing Discs 
Brazing Rings 
Brazing Shims 
Brazing Washers 
Custom Shapes 
Resale Options Brazing Paste 
Brazing Rod (Flux Coating Available) 
Brazing Strip 
Brazing Wire 
Spooled Brazing Material
Approx. Wire Length (BCuP/lb.) (BAg/Tr.oz) 1097 in; 0.062 diameter
4386 in; 0.031 diameter 
487 in; 0.093 diameter

Physical Constants

Solidus 1590 ºF
866 ºC
Liquidus 1630 ºF
888 ºC
Recommended Braze Temperature 1750 ºF
Density 0.302 lb./cu.in
Color Bronze


Suitable for ferrous and non-ferrous applications. Often an economical alternative to silver brazing alloys.


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-C
  • UNS: C68100


  • Brazing Temperature Range High: 1730 F / 943 C
  • Brazing Temperature Range Low: 1680 F / 916 C
  • Liquidus: 1630 F / 888 C
  • Solidus: 1590 F / 866 C



  • Cu: 58%
  • Zn: 39.95%
  • Sn: 0.95%
  • Fe: 0.75%
  • Mn: 0.255%
  • Si: 0.095%

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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