  The Kremer-Grest (KG) polymer model is a standard model for studying generic
polymer properties in Molecular Dynamics simulations. It owes its popularity to
its simplicity and computational efficiency, rather than its ability to
represent specific polymers species and conditions. Here we show, that by
tuning the chain stiffness it is possible to adapt the KG model to model melts
of real polymers. In particular, we provide mapping relations from KG to SI
units for a wide range of commodity polymers. The connection between the
experimental and the KG melts is made at the Kuhn scale, i.e. at the crossover
from chemistry-specific small scale to the universal large scale behavior. We
expect Kuhn scale-mapped KG models to faithfully represent universal properties
dominated by the large scale conformational statistics and dynamics of flexible
polymers. In particular, we observe very good agreement between entanglement
moduli of our KG models and the experimental moduli of the target polymers.
