S Glass Fiber Yarn also can called as High Strength Glass Fiber Yarn, because it is with the biggest strength compared others fiberglass Yarns.  S glass fiber is made from the magnesium alumino silicate glass system meeting the needs of military application. Now it contain H2, H4 and H6 series. Compared with E Glass Fiber Yarn, they exhibit 30-40% higher tensile strength, 16-20% higher modulus of elasticity, 10 folds higher fatigue resistance, 100-150℃ high temperature endure, also they have excellent impact resistance because of high elongation to break, high ageing and corrosion resistance, quick resin wet-out properties.