Let's compare the tensile strength of each material:

According to the Encyclopedia Britannica, compact bone specimens have been found to have tensile strength around 20,000 psi (pounds per square inch).

"Mild" steel such as AISI 1020 Hot Rolled, on the other hand, has a tensile strength of 70,000 psi, and alloy steels that are heat treated can have tensile strengths of over 200,000 psi, ten times stronger than bone.

However, this is not the whole story. Steel is about 4.5 times heavier than bone, so bone is actually stronger than mild steel on a per-weight basis. Engineers are taught ways if using lighter, weaker materials (like wood or bone) and making them behave as if they were stronger than steel. The college course in which you learn this is called "Strength of Materials" or "Mechanics of Materials".

Comparitivly speaking. Bone.

http://www.medicinenet.com/script/main/art.asp

http://web.mit.edu/newsoffice/2007/bone-0906.html

http://www.allbusiness.com/.../129191-1.html

1) "The human thigh bone is hollow but is the strongest bone in the body. Ounce for ounce, it has a greater pressure tolerance and bearing strength than a cast steel rod of equivalent size."
Source:
http://www.allbusiness.com/.../129191-1.html


2) "Thus, the mechanism responsible for bone’s strength at the molecular scale also explains how bone can remain so strong—even though it contains those many tiny cracks required for its renewal.

This could prove very useful information to civil engineers, who have always used materials like steel that gain strength through density. Nature creates strength in bone by taking advantage of the gaps that ensure continuous material renewal, which themselves are made possible by the material’s hierarchical structure.

“Engineers typically over-dimension structures in order to make them robust. Nature creates robustness by hierarchical structures,”"
Source and further information:
http://www.physorg.com/news107436882.html

Sticks and stones and weed and bones.