Human bones are stronger than steel by weight

Human bone represents nature's elegant material design, combining rigidity and flexibility surpassing many synthetic materials. Bone is a composite consisting of 70% mineral (calcium phosphate as hydroxyapatite) and 30% organic material (collagen protein). Hydroxyapatite provides rigidity and compressive strength, while collagen provides tensile strength and flexibility. This combination allows bone to withstand significant stress in multiple directions without fracturing. When measured by strength-to-weight ratio, human bone exceeds steel—a bone with the same weight as a steel beam can support greater loads. This is why aerospace engineers study bone structure to develop improved composite materials. Bone also adapts to stress through Wolff's Law, increasing mineral density in stressed regions. This adaptive capability combined with inherent strength-to-weight ratio makes bone remarkably efficient.