Applying a material such as oleic acid or extreme pressure oil on the precut surface in ductile metal cuttings can dramatically improve the machinability, due to a reduction in friction between the lamella of the chip. Under optimal conditions, this lubricant applying effect can reduce the cutting forces by more than 90%. In the wet cutting operation at machine shops, cutting fluids can reach the precut surface. Therefore, it is reasonable to assume that lubrication by the cutting fluids involves the lubricant applying effect. We have investigated the extent of lubrication by cutting fluids using oil-submerged cutting experiments. The results show that the lubricant applying effect has a major role in lubrication under certain conditions, offering the possibility of semi-dry machining.