Heat production associated with every machining operation has a significant effect on the cutting temperature and drilling time. Such effect is mitigated through the application of cutting fluids that would help to conduct off the generated heat actuated by the frictional contact between the tool and workpiece cutting zone. The effects of the vegetable oils (Gmelina oil, Neem oil and Castor oil) and conventional soluble oil on the cutting temperature and drilling time were studied at various spindle speeds, feed rates and cutting speeds. The vegetable oils were extracted from their various seeds using solvent and pressing method. A minimum quantity lubricating (MQL) system was set-up and was used to control the flow of the cutting fluid to the drilling zone of the tool-workpiece interface. A vertical drilling machine having a 20mm drill bit size was used to drill a through hole of 40mm depth on a mild steel material. During the drilling process, the cutting fluid was applied to the drilling zone using the MQL system and the cutting temperature and drilling time were measured with an infra-red thermometer and a stop watch respectively. The results gotten from the experiment showed that Gmelina oil gave the lowest cutting temperature and drilling time. This was followed by soluble oil, Neem oil and then Castor oil. Under a dry drilling condition, the cutting temperature and drilling time obtained were the highest compared to other cutting fluids applied conditions. Therefore, cutting fluids application reduces the cutting temperature and drilling time and should be employed in industrial operations for the attainment of good machining characteristics.

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