4-19. Induction Heat Soldering
General. The induction heat method of soldering employs a principle of heat application totally different from any
conduction or convection process discussed earlier. in this method, heat is not actually applied to the assembly to be
soldered, but rather, heat is generated within the assembly itself by exposure to an electromagnetic field.
Induction Heat Soldering Equipment. The induction heat soldering equipment consists of the following:
A high-frequency generator to produce a high-frequency alternating current.
A water-cooled metal coil, attached to the high-frequency generator, to carry the high frequency alternating
current that produces an electromagnetic field within the coil.
Uses. The induction method of soldering is very useful in the soldering of:
Large or massive pieces of metal.
Small metal parts where it is desired to confine the heat to some particular section of the assembly.
Soldering multiple metal assemblies at one time that would become oxidized if heated with a flame or torch.
Soldering units where the point of soldering could not be reached by the tip of a soldering iron.
Chain soldering, where the parts are placed on an endless belt which travels through the electromagnetic field at
a constant rate of speed.
Advantages. The main advantages for using induction heat soldering compared to conduction or convection methods
are as follows:
The metal is quickly and efficiently heated at the exact point where it is needed.
The metal does not warp, discolor or oxidize.
Selecting Flux. Select a stable and fairly concentrated flux which will withstand the sudden influx of heat without
decomposition. Concentrated chloride fluxes or resin fluxes are best adapted to induction heat soldering.
Section IV. USE OF ABRASIVES AND FILES
4-20. Abrasive Processes.
General. Processes and materials discussed in this section, use abrasive grains for shaping work pieces. Abrasive
grains are hard crystals either found in nature or manufactured. The most commonly used materials are aluminum oxide,
silicon carbide and diamond. Other materials such as garnet, zirconia, and glass are used as abrasives for some