This paper details the relationship between tool wear properties and nitrogen impurities in diamond tools. Micro FT-IR analysis was carried out to determine the quantity of nitrogen impurities. The results show that nitrogen impurities significantly affect chipping and crater wear. Tools that contain more nitrogen impurities show less chipping. Crater wear volume corresponds to the quantity of nitrogen impurities in synthetic diamond tools and is affected by heat conduction and strength. Key words: diamond tool, precision cutting, Micro FT-IR, nitrogen impurities, chipping, crater wear, redox reaction.