GUN DRILL COOLANT AND OPERATING GUIDELINES THE RIGHT COOLANT Neat Oil Water Soluable • Oil is preferred over water soluable coolant • Used on most CNC machines • Most conventional gundrilling machines use oil • Provides superior lubricity, better tool life and surface finish <8% = unacceptable • No worry about concentration levels 10-12% = acceptable • Does not evaporate 12-15% = preferred CUTTING CONDITIONS 709