  We construct hyperasymptotic expansions for the heavy quark pole mass
regulated using the principal value (PV) prescription. We apply such
hyperasymptotic expansions to the $B/D$ meson masses, and $\bar \Lambda $
computed in the lattice. The issue of the uncertainty of the (top) pole mass is
critically reexamined. The present theoretical uncertainty in the relation
between ${\bar m}_t$, the $\bar{\rm MS}$ top mass, and $m_{t, \rm PV}$, the top
pole mass regulated using the PV prescription, is numerically assessed to be
$\delta m_{t,\rm PV}= 28\;{\rm MeV}$ for ${\bar m}_t =163$ GeV.
