Аннотация:AbstractThis study investigates the effect of CuO, TiO2, Al2O3, and multiwalled nanotube (MWNT) nanoparticles at various treat rates on the tribological properties, namely, wear, coefficient of friction (COF), and pressure of seizure (poz), of metalworking fluids during lubricating processes in diverse industrial applications. Results are reported based on two methods: wear scar diameter (WSD) and COF by ASTM D5183 and poz by the Institute for Sustainable Technologies–National Research Institute (ITEePib) Polish method for testing lubricants under scuffing conditions. Results showed significant improvements with small filler concentrations of nanoparticles. CuO nanofluids showed a diminishment of 86% for WSD at 0.01 wt%, whereas TiO2 resulted in an increase in poz of up to ∼250% at 0.05 wt% compared to pure conventional fluid.KEY WORDS: Extreme Pressure AdditivesAntiwear AdditivesCutting FluidsDrawing FluidsNanofluids