What material holds the most <span title="contracting/torsion/compression/lateral">contracting/torsion/compr...</span> bending force for it's size and weight?

Question

Referring to mechanical and not chemical potential energy. I'm looking for something small enough to carry and relatively obtainable, but it would be interesting to know THE material capable of holding the most force without breaking.

Answer 1

THE material would be carbon nanotubes (or graphene if you want to look at it in 2-D) - small enough to carry but they are relatively unobtainable.

Answer 2

Materials that have the range of strengths that you require will must likely be metals.  However, based on size and weight is a tough one, since those two attributes tend to be inversely proportional.

From a very general perspective, 7075-T6 Aluminum can have yield strengths up to about 73ksi and only weigh about 0.1 lbs/in^3.  On the other hand 17-4PH cond H900 can have yield strengths up to 180,000ksi but weigh in at .28 lbs/in^3, almost three times heavier.  

In comparison, a strength/weight ratio would show the aluminum to have the edge, but one must consider a vast array of other properties dealing with the application and environmental perspectives of the intended use of the material.

This is only two materials of thousands of possibilities.  That said, these two materials are very readily available from a variety of sources..