Solder Connection

Solutions in Soldering Technology

Johnson Matthey SILFOS 5

Sil-fos™5 is a 5% silver-copper-phosphorus brazing filler metal, which is used to braze copper and copper alloys. When brazing copper the phosphorus within the alloy imparts a metallurgical based self-fluxing capability. When Sil-fos™5 is used to join copper alloys (such as brass, bronze or gun metal) a separate flux will be required because the self-fluxing action only occurs on copper (see below for details). 

This filler metal should not be used to braze iron containing materials like carbon or stainless steels or nickel containing materials as the phosphorus within the filler metal will form brittle, intermetallic, phosphide compounds,at the joint interface. Sil-fos™5 is not suitable for use in sulphurous atmospheres at elevated service temperatures.

Key Products Features & Benefits: 

  • 5% Silver (Ag) - 89% Copper (Cu) - 6% Phosphorous (P)
  • Melt Range - 644-815 ºC
  • Classified as CP 104 to EN1044 1999 Specification.
  • Classified as CuP 281 to ISO17672 2010 Specification
  • Commonly available as a 2.0mm Dia. rod as 
  • Standard 600mm long


Data Sheets and Info

Technical Bulletin

Product Guide

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