In this study the performance of uncoated and TiN coated M35 and M2 quality cutting tools (drills, tabs and reamers) during machining of refrigerator compressor motor blocks made of GG 25 quality cast iron was investigated. In uncoated condition M35 quality cutting tools exhibited longer tool life than M2 quality cutting tools. TiN coating caused further improvement on the tool life of M35 quality cutting tools. Depending on the coating condition, tool lives increased to 2.2 to 4.0 times for reamers and drills and 32 to 36 times for tabs with respect to uncoated M2 quality cutting tools. The coating conditions that provide longer roughness, higher hardness and higher adhesion achieved longer tool life.