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Stay-Silv® Black Paste Brazing Flux 5 lb. jar


Stay-Silv® black paste brazing flux 5 lb. jar


Stay-Silv® black brazing flux is an all-purpose, high-temperature, homogenous flux for use in silver brazing. It is formulated to provide smooth flux application, even coverage, and excellent protection during brazing. The addition of boron extends the active life of the flux enabling it to withstand longer heating cycles. This makes it an ideal choice for induction brazing where intense localized heating is a factor, or heavy parts that often require longer heating time. Stay-Silv black flux is recommended for brazing copper and copper alloys, (except aluminum bronze), steel, and other ferrous base metals. It is often used in brazing stainless steel, nickel alloys, and tungsten carbide. Stay-Silv black flux is used with many high silver brazing filler metals of the AWS A5.8 BAg classifications and ISO 17672 class Ag alloys. It is also suitable for use with many phosphorus-copper-silver alloys, (AWS BCuP and ISO CuP), for brazing copper to brass. Black flux turns clear, (transparent), close to brazing application temperature. This is a useful indicator in timing braze wire application. Complies with the EU Reach & RoHS directive.


  • High-temperature, all-purpose black flux for silver brazing
  • Formulated for applications where the work is subjected to rapid, localized heating
  • Ideal for applications where large amounts of refractory oxides may form
  • Used with stainless steel, carbide, heavy parts, prolonged heating cycles
  • The flux turns clear (transparent) close to brazing application temperature, indicating the best time for braze wire application
  • Used for silver brazing, including stainless steel, and brazing heavy parts and carbides


Warning -

Cancer and Reproductive Harm -

Warranty Information

  • 1 Year

What's Included

  • Stay-Silv® black paste brazing flux 5 lb. jar




Alloy Type Aluminum Brazing
Chemical Composition Zinc 98%
Aluminum 2%
Classification Manufactured to Harris Products Group's internal engineering standards
Diameter 2mm (0.08 in.)
Liquidus 824°F (440°C)
Material Aluminum Brazing Alloy
Melting Range 710°F - 725°F (377°C - 385°C)
NSF Compliant No
Recommended Flux No additional flux is required as AlCoR contains a cesium-fluoroaluminate (CsAlF) type flux in an internal core.
Recommended Joint Clearance 0.003 in. - 0.005 in. (0.076mm - 0.127mm)
RoHS Compliant Yes
Size 1 ea. cup
Solidus 824°F (440°C)
Typical Application Joining aluminum alloys of the 1000, 3000 and 6000 series
Joining aluminum to copper
Repairing heat exchangers, air conditioners, aluminum alloy condensers, etc.


Warranty 1 Year