Filler wire is a type of welding consumable used to add material to a weld joint, ensuring strong and durable connections between metal pieces during the welding process. Typically made from metals that match or complement the base materials being welded, filler wires can vary in composition, diameter, and coating depending on the specific welding technique employed—such as MIG (Metal Inert Gas) or TIG (Tungsten Inert Gas) welding. The filler wire is fed into the weld pool, where it melts and fuses with the base metals, creating a solid bond as it cools. Its proper selection is crucial for achieving optimal weld strength, corrosion resistance, and overall performance of the finished joint. Filler wire plays a vital role in various industries, including construction, automotive, and manufacturing, where reliable and high-quality welds are essential.