Four-ball tests using 12.7 mm diameter steel bearing balls have been conducted to evaluate the wear and friction reducing properties of admixtures of paraffin oil with potentially active 1-[2-(6-substituted)benzothiazolyl]-thiocarbamides and a sulphurphosphorous commercial additive (0.5% wt/vol). The parameters determined are wear-scar diameter, friction coefficient, initial seizure load, 2.5 s seizure delay load, weld load, mean Hertz load and flash temperature parameter, The additive, 1-[2-(6-Chloro)benzothiazolyl]-thiocarbamide appeared to be the most effective. The topography and tribochemistry of the wear-scar surface have been studied by SEM and AES techniques, respectively.