What is Flux

  Definition of Flux

The most commonly asked question we receive from people who have never worked with fluxes is:

 "What is flux?"

FLUX: A chemical composition critical to the heat joining methods of soldering, brazing, and welding that:

1. Chemically:  Cleans metals surfaces to assist the flow of filler metals over base metals. Provides a protective barrier against re-oxidation and heat scale.

2. Thermally: Assists with heat transfer from heat source to metal surface.

3. Physically: Helps in the removal of surface metal oxides.

Definitions  of Different Heat Joining Processes

SOLDERING: A process whereby similar or dissimilar metals are joined using an alloy that typically includes a base of tin combined with lead, silver, antimony, bismuth, and indium. Soldering processes cover a temperature range of 60°C - 440°C/140°F - 850°F. Used in electronics, plumbing, food industry, electrical wiring and automotive applications.

 BRAZING: A process whereby similar or dissimilar metals are joined using an alloy that typically includes a base of silver combined with nickel, copper, and zinc. High temperature brazing, generally used for carbide products, uses alloys that contain no silver but use nickel, copper, and manganese. Brazing covers a temperature range of 470°C -1,190°C/900°F - 2,200°F. Used for compressors, engine circulation tubes, mining tools, plumbing fixtures, jewelry, musical instruments.

 WELDING: A process whereby similar metals are joined using a direct heat source to melt the base metal and a filler metal to create a uniform finished product. Most welding involves iron-based metals such as steel and stainless steel. Welding covers a temperature range of 800°C - 1635°C/1500°F - 3000°F. Used for forge and farrier applications, oil pipelines, and blacksmithing.