The cold rolling process is decisively influenced by the mechanisms of
lubricant supply to the deformation zone. Rolling tests with thin alu
minium sheets were performed based on a theoretical model of the hydro
dynamic entrainment of lubricant. Aluminium was used as a model materi
al for steel in order to get a soft rolling stock to enlarge the hydro
dynamic effect. The rolling conditions were chosen so that changes in
friction conditions could definitely be traced back to a hydrodynamic
effect in the inlet zone. The changes in friction conditions were demo
nstrated by significant rolling parameters, dimensionless similarity n
umbers, and alterations of the surface structures of the rolled test s
heets. The conclusions indicate some tribological problems in cold rol
ling.