The metal-working industry is increasingly interested in synthetic metel-working fluids and coolants. Also a environmental aspect of the treatment of used fluid is important. The excellant lubricating properties of polyalkylene glycols and fatty acid have been recognised in the area such as hydraulic fluids and compressor lubricants. The main purpose of this study was to investigate the cutting properties of polyethylene glycol and its synergy effect with a common fatty acid, against steel, bronze and aluminum using drilling machine. From the study, it was shown that there were some synergy effects of the cutting lubricant depend on the cutting condition as load and cutting metals.