Segmentation by type classifies aluminium welding wires according to alloy composition and filler characteristics, each influencing weld metallurgy and mechanical outcomes. The dominant ER4043 (Al‑Si alloy) segment, representing roughly 45 % of type‑level sales, is prized for its fluidity, low cracking tendency, and suitability for a broad range of aluminium grades, especially in automotive and construction. ER5356 (Al‑Mg alloy) follows with about 30 % share, offering superior tensile strength and corrosion resistance, making it the preferred choice for marine and aerospace structures where load‑bearing capacity is critical. ER5554 (Al‑Mg‑Si alloy) occupies near 15 % of the market, providing a balance of strength and ductility for high‑temperature applications. Niche alloys such as ER5183 and ER4047 together account for the remaining 10 %, serving specialized sectors like high‑speed rail and defense where specific alloy compatibility or enhanced weldability is required. The relative weight of each type directly impacts total market volume, as end‑users select wires that align with design specifications, cost constraints, and certification standards.