FLUIDS and compounds are the SUBSTANCES used for efficient cutting while cutting operations take place.It helps in COOLING the tool as well as the work-piece. It ALSO reduces the friction between the chip and the tool FACE by lubricating.There are many types of cutting fluids likeStraight mineral oilsChemical Solution (Synthetic fluids)Compounded or blended oilFatty oilsSoluble oils (Emulsified oil-suds)Since carbide has a high value of hot hardness thus for cooling tools like carbide soluble oil in plant coolant is used.Since soluble oil has high cooling capabilities and good lubrication because of the blending of oil and water.They also provide a protective oil film on moving components of machine tools and resist emulsification of greases and slideway oils. A chart showing coolants for different metals is given below:MaterialDrillingTurningAluminiumSoluble oilKeroseneKerosene and lard oilSoluble oil BrassDry soluble oilMineral oilLard oilSoluble oil BronzeDry soluble oilMineral oilLard oilSoluble oil Cast ironDryAir jetDry CopperDrySoluble oilMineral lard oilSoluble oil Steel alloysSoluble oilSulphurized oilMineral lard oilSoluble oil General purposes steelSoluble oilSulphurized oilLard oilMineral lard oilSoluble oil