  Steering, a quantum property stronger than entanglement but weaker than
non-locality in the quantum correlation hierarchy, is a key resource for
one-sided device-independent quantum key distribution applications, in which
only one of the communicating parties is trusted. A fine-grained steering
inequality was introduced in [PRA 90 050305(R) (2014)], enabling for the first
time the detection of steering in all steerable two-qubit Werner states using
only two measurement settings. Here we numerically and experimentally
investigate this inequality for generalized Werner states and successfully
detect steerability in a wide range of two-photon polarization-entangled Bell
local states generated by a parametric down-conversion source.
