Basically MQL delivery systems are of two types: External minimal quantity lubrication (MQL) and internal minimal quantity lubrication (MQL). External minimal quantity lubrication (MQL) System consists of a coolant tank or reservoir which is connected withtubes fitted with one or more nozzles. The system can be assembled near or on the machine and has independently adjustable air and coolant flow for balancing coolant delivery. It is inexpensive, portable, and suited for almost all machining operations. Internal minimal quantity lubrication (MQL) systems here air-oil mist is created .The oil and pressurized air is mixed and fed on the job through the spindle near to the tool and the cutting zone interface