Cutting oil, or cutting fluid, is a coolant/lubricant used specifically while machining parts. Although there are many types of fluids, but here at MadTown, we only use coolant. It can be referred as cutting compound, coolant, or more commonly, cutting fluid, depending on the process and machine it is being used in. It is a necessary component of machining and manufacturing.
Good cutting fluids allow for the temperature of a piece of material to be kept stable, especially when working with tolerances. It allows for the the drill bits to last longer before being worn out. It also prevents any of the machine parts or bits to rust. Lastly, the people handling the fluids are safe from any toxicity or damage to their bodies.
Most pieces/materials will require the use of cutting fluid as it helps protect the part and the drill bits that are being utilized. Usually the materials utilized (6061-aluminum, various grades of steel) for parts do not require as much.