AWS Definitions

Nickel Bronze (C-04™) AWS A5.8 Class RBCuZn-B

Brazing filler metal RBCuZn-B (low-fuming brass-nickel) is used for the brazing and braze welding of steel, cast iron, copper, copper alloys, nickel, and nickel alloys. It is also used for the surfacing of steel, as well as with torch, induction and furnace processes. RBCuZn-B braze welding rods are similar to RBCuZn-A rods but contain additions of iron and manganese that serve to increase the hardness and strength. In addition, a small amount of silicon (0.04% to 0.20%) serves to control the vaporization of the zinc, yielding the "low-fuming" property. Fluxing is generally required, and a borax-boric acid type flux is commonly used. Joint clearances from 0.05 mm to 0.13 mm.

Low Fuming Bronze (LFB) AWS A5.8 Class RBCuZn-C 

Brazing filler metal RBCuZn-C is used on steel, copper, copper alloys, nickel, and nickel alloys. It is used with torch, furnace, and induciton brazing processes. Fluxing is required, and a borax-boric acid flux is commonly used. Joint clearences from 0.05 mm to 0.13 mm [0.002 in to 0.005 in] are suitable.

Nickel Silver (GF-72) AWS A5.8 Class RBCuZn-D

Brazing filler metal RBCuZn-D (referred to as nickel silver) is primarily used for brazing tungsten carbide. It is also used with steel, nickel, and nickel alloys. It can be used with all brazing processes. This brazing filler metal is unsuitable for furnace brazing in a protective atmosphere.