  Driven quantum materials often feature emergent topology, otherwise absent in
static crystals. Dynamic bulk-boundary correspondence, encoded by
nondissipative gapless modes residing near the Floquet zone center and/or
boundaries, is the most prominent example of such phenomena. Here we show that
topologically robust gapless matallic states appear along the grain boundaries,
embedded in the interior of Floquet topological crystals, when the
Floquet-Bloch band inversion occurring at a finite momentum (${\bf K}^{\rm
Flq}_{\rm inv}$) and the Burgers vector (${\bf b}$) of the constituting array
of dislocations satisfy ${\bf K}^{\rm Flq}_{\rm inv} \cdot {\bf b}=\pi$ (modulo
$2 \pi$). Such dissipationless metallic states can be found near the center
and/or edge of the Floquet Brillouin zone, irrespective of the drive protocol.
We showcase these general outcomes for two-dimensional driven time-reversal
symmetry breaking insulators. Promising experimental platforms, unveiling such
dynamic topological metals in real materials, are discussed.
