It is generally called MQL (Minimal Quantity Lubrication). It does not use coolant fluid. Very small quantity of vegetable oil (not containing harmful item nor pollution item) is blown to the cutter in micro-mist. Thus, the following effects are obtained.
1) The adequate lubricity is given to the cutter >> High cutting power
2) Cutter is cooled by cooled air-blowing >> Longer tool life
3) Small chips are blown away by air-blowing >> Fine surface roughness

Suitable Cuttings
Semi-DRY CUT method is suitable to High Speed, High Feed cuttings. (In other words, it suits to High RPM of comparatively small diameter cutter.) In high RPM cutting, coolant fluid is splashed out and can hardly reach the cutter. But, micro-mist is whirled into hole or cutting edge by high RPM rotation of cutter and makes thin molecular-order lubrication film of "ULTIMA". In finishing, small chips are blown away, and very fine surface is obtained. Besides, the compressed air is cooled when being blown out from the nozzle, and it cools the cutter.

Not Suitable Cuttings
Semi-DRY CUT method is not so suitable to Low Speed, Heavy Cuttings. It generates too high heat and chips are too large. We suggest to change cutting method or use both coolant fluid and micro-mist according to the cutting conditions.