Solid wire is a solid metal wire used in welding that can fill the interior of metal or serve as a conductive material simultaneously. In tungsten inert gas (TIG) welding, solid wire is used as a filler metal, while in shielded metal arc welding (SMAW), submerged arc welding (SAW), or other gas metal arc welding (GMAW) processes, it acts as a conductive electrode.

It can be coated with an anti-oxidation flux on the surface to enhance its relevant properties. The entire manufacturing process of the product is quite rigorous. Since the materials used in solid wires often come from steel sheets or flux components, their dimensions and chemical compositions must be carefully checked before manufacturing to ensure the quality of the solid wire products.

Due to the limited internal space, the particle size becomes crucial at this point. The particles are often tightly bound together like water molecules, and the elemental composition inside may not be perfectly uniform.

Most solid wires are formed by passing a flat metal strip through a series of processes to create a U-shaped cross-section. Granular flux is then filled into the metal groove, and through a sealing and rolling process, the flux is tightly pressed inside the tubular wire. After a series of operations, the tubular solid wire is drawn into the desired product. The drawing action at this stage also helps to evenly fix the filler within the solid wire substrate, although partial hollow areas without flux may form during production.

In addition, the surface of the wire must be smooth and flat, which facilitates cleaning and affects the transmission of welding current. The finished solid wires are typically coiled into rolls, packaged with plastic sleeves, and stored in dry places to prevent moisture. After packaging, the materials are placed in cardboard boxes and delivered to users. For thicker sections, butt joints are mostly used, and solid wires contain less flux.

Advantages of Solid Wires:
Strong Adaptability to Various Steels: They can be easily adjusted by modifying the flux composition and ratio to provide the required weld chemical composition, showing strong adaptability to welding different steel types.
Good Process Performance and Beautiful Weld Formation: Using gas-flux combined protection, they achieve excellent weld formation. Arc stabilizers ensure stable arcing and uniform metal transfer.
High Deposition Rate and Productivity: Under the same welding current, solid wires have a higher current density and faster melting speed, with a deposition efficiency of about 85%–90%. Their productivity is 3–5 times higher than that of stick electrode welding. They can also be used for all-position welding with higher welding currents.
Disadvantages:
Complex manufacturing process;
More difficult wire feeding compared to solid wires during welding.