# Which of the following is not a function of flux?
A. To remove any oxide coating on parent metal
B. To restrict the flow of solder over the parent metal
C. To protect metal surface from oxidation during soldering procedures
D. To permit the flow of solder over parent metal
The correct answer is B. To restrict the flow of solder over the parent metal, this is the function of antiflux, not flux.
The Latin word ‘flux’ means flow. For a solder to wet and flow properly, the parent metal must be free of oxides. This is accomplished with the help of a flux.
FUNCTION OF FLUX
1. To remove any oxide coating on the parent metal.
2. To protect the metal surface from oxidation during soldering.
TYPES
Fluxes may be divided into three activity types.
- Protective: This type covers the metal surface and prevents access to oxygen so no oxide can form.
- Reducing: This reduces any oxide present to free metal and oxygen.
- Solvent: This type dissolves any oxide present and carries it away. Most fluxes are usually
combination of two or more of the above.