11. Forms have been made using nearly every common structural material including air pressure supported fabric. 12. Teflon and aerogel are structural materials , polymers, for which the monomers may exist in nature. 13. This significantly reduces the cost associated with structural materials . 14. With the exception of structural metals, such as steel, all structural materials creep over time. 15. For multi-directional and out-of-plane loading cases, textile composites are widely used as high performance structural materials . 16. Flint is the other predominant structural material : its local abundance has ensured its frequent use. 17. Typical uses for molded plastics include molded furniture, molded household goods, molded cases, and structural materials . 18. Each cell incorporates structural material and a reversible interlock, allowing lattices of arbitrary size and shape. 19. The Courthouse exhibits an early use of iron as a structural material in a federal building. 20. Cast iron was not yet a structural material , or capable of being worked at this scale.
