Cutting Fluids: Functions, Properties

Cutting fluid cools the workpiece and tool by carrying away the heat generated during machining.
It acts as a lubricant at the friction zones, increasing tool life.
As friction decreases, the forces and electricity power consumption decrease.
Cutting fluids produces a better surface finish for the workpiece.
It causes to break the chips into small pieces.
It washes away the chips from the tool.
It prevents the corrosion of chips and machines.
Improves dimensional accuracy and control of the workpiece.
It permits maximum cutting speed; hence, the time for machining is reduced, and the cost of manufacturing increases.

Cutting fluids should have low viscosity to permit free liquid flow.
It should possess good lubricating properties.
It should have high specific heat, high heat conductivity and heat transfer coefficient..
It should be non-corrosive to work and machine.
It should be non-toxic to the operating person.
It should be odorless.
It should be stable in use and storage.
It should be safe.
It should permit a clear view of the work operation.

Cast Iron: No cutting fluids are used.
Steels: Lord oil with mineral oil is used.
Alloy steel: Sulphur brass oil with mineral oil is used.
Copper: Soluble oil with 90 to 95% of water is used.
Aluminium: Mineral oil with soluble oil cutting fluids are used as cutting fluids.