Properties of Spider Silk

Spider silk is a family of protein fibers whose properties vary with spider species and thread function. Some silks combine high tensile strength, low density, and substantial extensibility, so certain varieties can exceed steel in specific strength (strength per unit mass). But the claim “stronger than steel” depends on whether one compares tensile strength, stiffness, toughness, or equal mass. Researchers are engineering recombinant spidroins and biomaterials with potential uses in tissue engineering, sutures, and composites; reproducing natural silk at scale with its full structure and properties remains challenging.