The presented work aims to investigate minimum quantity lubrication (MQL) using cutting oil with/without Al2O3 nanoparticles for hard milling of 60Si2Mn steel (50-52 HRC) using carbide inserts. The effects of three different types of based cutting oils including emulsion, soybean oil and rapeseed oil on surface roughness Ra, Rz and tool life were studied and investigated. The experimental results show that the use of Al2O3 nano cutting oil has improved lubrication capability compared to base cutting oil, contributing to improve machined surface quality and tool life. Al2O3 emulsion-based nanofluid exhibited the best performance among the three surveyed oils, followed by rapeseed oil and finally soybean oil. Furthermore, the cutting speed of the carbide inserts was improved and the tool life was significantly increased with the help of nano cutting oil due to the improvement in lubrication effects in the cutting zone, thereby helping to reduce cutting forces and cutting heat.