Which welding process does NOT require the application of pressure?

The correct answer, which is that none of the welding processes listed requires the application of pressure, is significant because each welding technique operates under different principles that don't involve the application of force or pressure as a key component of the process.

TIG (Tungsten Inert Gas) welding uses a non-consumable tungsten electrode to produce the weld. The process relies on an electric arc to melt the base material and filler material (if used), and it does not utilize pressure to join materials. Instead, it depends on the heat generated by the arc to create a fusion between the workpieces.

SMAW (Shielded Metal Arc Welding), also known as stick welding, similarly focuses on generating heat through an electric arc between the electrode and the workpiece. The process relies on the melting of the electrode and the base material due to this heat, without requiring additional pressure to achieve a weld.

FCAW (Flux-Cored Arc Welding) employs a flux-cored electrode and also operates through an electric arc. It melts the filler material and base metal using the heat from the arc, rather than applying mechanical pressure.

Overall, all the processes mentioned waste no effort on exerting physical pressure; they rely solely on the heat produced from the electrical energy