Ti-6Al-4V pins were slid against SS316L disks in pin-on-disk arrangement using pins of different diameters; with the contact pressure maintained the same for all experiments under ambient and vacuum conditions. Characterization of the tribological samples was performed using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), and X-ray diffraction (XRD). The tribological behavior was found to be governed by strain rate response (SRR), tribo-oxidation (TO), formation of a mechanically mixed layer (MML), and frictional heating which can affect each of the above factors. For a particular set of experiments (ambient/vacuum), variation of wear-rate with respect to sliding speed were found to follow the heat flux in each set. Propensity of this material to undergo softening due to frictional heating and strain rate effects is reflected in the tribological response.