A progressive increase in the desire for environmentally friendly lubricants by users and strict government regulations for the use of these lubricants has provided an opportunity to use plant oils as biodegradable lubricants, therefore vegetable oils have been investigated to replace oil lubricants because of their maintaining the conditions of nature (environment) properties. In this paper, the influences of the blending ratio of mustard seeds oil with commercial mineral oil (SAE40) on the tribological characteristics were investigated and compared with mineral oil using the four-ball tribotester. Mustard seeds oil was blended with mineral oil at a volumetric ratio ranging from 22.5 to 90%. All experimental works were confirmed to ASTM D4172-B standard. The results exhibit that some blends of mustard seeds oil with mineral oil have lower wear scar diameter, friction torque, Friction coefficient and a higher parameter of flash temperature value compared to mineral oil and neat mustard seed oil. In conclusion, the mustard seed oil blend (MU22.5) shows a better anti-wear and anti-friction performance compared to oil samples. Therefore, mustard seeds oil has the potential to be used as a lubricant of mating surfaces.
