The S‑Glass Fibre Yarn segmentation by application isolates five principal end‑use categories that collectively drive market volume. Composites reinforcement accounts for the largest share, roughly 45 % of total sales, as manufacturers of wind‑turbine blades, marine hulls, and sporting‑goods structures rely on the high tensile strength and low density of S‑glass yarn to meet performance targets. Electrical insulation follows with an estimated 25 % contribution, reflecting the yarn’s superior dielectric properties used in transformer windings, cable sheaths, and printed circuit board substrates. The automotive components segment represents about 15 % of the market, where S‑glass yarn is incorporated into brake pads, under‑body panels, and lightweight interior parts to reduce weight while maintaining crash‑worthiness. Aerospace structures contribute roughly 10 %, supporting applications such as fuselage skins and interior panels that demand stringent fire‑resistance and fatigue performance. Finally, construction panels hold the remaining 5 %, primarily in fire‑rated wallboards and prefabricated panels. These percentages illustrate how each application underpins the overall S‑Glass Fibre Yarn market size.