When using FCAW wire, where is the flux located?

Flux-cored arc welding (FCAW) uses a hollow wire filled with flux material, which is integral for the welding process. The flux is housed within the wire itself, allowing it to provide shielding gas upon melting, as well as to produce slag that protects the weld pool. This internal flux not only helps in stabilizing the arc but also provides necessary alloying elements to enhance the quality of the weld.

The other options refer to locations that do not contain the flux in FCAW. The outside of the wire does not contain flux, as the main purpose of the hollow structure is to encase the flux internally. The welding gun does not hold the flux but instead delivers the welding wire to the weld pool. Likewise, the gas cylinder is used for delivering external shielding gas, which is not a requirement for all FCAW processes, especially those that utilize self-shielding flux-cored wire. This is why the only correct choice is that the flux is located inside the wire.