Strength to Weight Ratio (Specific Strength)

In the axial mode, this is simply ultimate tensile strength divided by density. In many applications, yield strength is preferred, because it is a more appropriate criterion of failure. However, the use of ultimate strength is a strongly established convention. In the bending mode, it is calculated as UTS^2/3/density. This corresponds to a scenario where section area is the free variable in an otherwise specified beam. In both cases, the derived units have little physical significance, and "points" are used instead.