The 4 Categories of Metalworking Fluids
1. Soluble Oil (Emulsion)Milky White
Composition: ~50% Mineral oil based. Mixed with water.
Best Lubricity
Rot/Bacteria prone
Good for Aluminum
"Monday Morning Smell"
2. Semi-SyntheticTranslucent Blue/Clear
Composition: 5-30% Mineral oil + polymers.
Good Balance
Can foam in soft water
Cleaner than oil
Moderate Lubricity
Best For: General Purpose Job Shops (Mills & Lathes).
3. Full SyntheticClear / Dyed
Composition: 0% Oil. Pure chemical polymers.
Zero Bacteria/Rot
Sticky residue
Excellent cooling
Poor Lubricity (Tapping)
4. Straight OilAmber Oil
Composition: 100% Oil. No water.
Ultimate Surface Finish
Fire Hazard
Tool life (Swiss)
Smoking / Mist
Best For: Swiss Lathes, Medical Titanium, Gun Drilling.