According to Materials Today, manufactured alloy steels can be 10 times better in tensile strength than bones and also 10 times better in fracture toughness and strain. Bones have a tensile strength of 150 MPa, a fracture toughness of 4MPa(m)1/2 and a strain-to-failure of 2 percent.
Bone is not as dense as metal, which makes bones lighter and helps them promote easier movement. Bones, as biological components, are subject to self repair, while metals are not. The elastic energy of steel is about the same as bone, but steel has 25 times more energy absorption. A carbon fiber has similar total energy but 10 times more elastic energy than bone.