  The RI/MOM non-perturbative renormalization scheme is studied on the lattice
in SU(3) quenched QCD with Wilson fermions. The gauge dependence of some
fermion bilinear renormalization constants is discussed by comparing data which
have been gauge-fixed in two different realizations of the Landau gauge and in
a generic covariant gauge. The very good agreement between the various sets of
results and the theory indicates that the numerical uncertainty induced by the
lattice gauge-fixing procedure is moderate and below the statistical errors.
