BB116 - 1.6mm Bare Low Fuming Bronze Brazing Rod (RBCuZn-C)

Technical Overview: RBCuZn-C Bare Bronze

The BB116 Low Fuming Bronze (Bare) is a high-performance copper-zinc brazing alloy classified under AWS A5.8 RBCuZn-C. This 1.6mm (1/16") filler metal is engineered for the oxy-fuel brazing of steels, cast irons, copper, and some nickel alloys. The alloy is formulated with small additions of manganese, iron, and tin, which serve multiple metallurgical functions: they increase the mechanical strength of the deposit, improve hardness, and significantly reduce the volatilization of zinc (fuming) at brazing temperatures.

Metallurgically, the iron and tin content promotes the formation of a fine grain structure within the solidified bead, enhancing both tensile strength (typically 50,000 - 60,000 PSI) and ductility. This makes the deposit resistant to cracking under stress and allows for substantial machining after application. The rod has a melting range of approximately 1590°F to 1630°F (866°C - 888°C). Since this is a bare rod, the use of a supplemental borax-boric acid flux is mandatory to dissolve surface oxides and promote wetting. The absence of a pre-applied flux coating gives the operator complete control over flux application, which is often preferred in precision applications or when dip-fluxing is utilized.

When used with a neutral or slightly oxidizing flame, the rod exhibits excellent flow characteristics and capillary action, penetrating deep into tight joints. It is particularly effective for "braze welding" where large fillets are built up without melting the base metal, minimizing heat distortion and the formation of brittle intermetallic compounds often associated with fusion welding of cast iron. It is also suitable for TIG brazing (GTAW) applications using AC or DCEN current, although oxy-fuel remains the primary method of deposition.

Key Technical Specifications

• AWS Classification: RBCuZn-C
• Solidus Temperature: ~1590°F (866°C)
• Liquidus Temperature: ~1630°F (888°C)
• Tensile Strength: Up to 65,000 PSI (depending on base metal)
• Brinell Hardness: 80 - 100 HB