Lubrication characteristics of Ov oil and castor oil. (a) Schematic of experimental setup. Coefficient of friction (CoF) for the tribological tests performed with Ov oil and castor oil at different temperatures for the duration of 3000 cycles. (b) CoF measurements for Ov and castor oils at 25 °C, 100 °C, 150 °C, and 200 °C. (c) Wear rate of steel surfaces used in CoF measurements for both Ov and castor oils.