Coolant can dramatically affect the performance of cutting tools, which can
impact the cost of your operation. Consider these guidelines for using coolant:

Cutting fluids perform two basic functions in drilling, milling, and threading:
1. to reduce heat generated in cut;
2. to lubricate the tool.

Water-based coolant helps to cool the chip when it is sheared from the workpiece material.

Work hardening of materials is a condition that should be avoided while machining. It is caused when heat generated by the cutting tool transfers to the workpiece material and causes plastic deformation. The process is similar to a heat treatment of the workpiece but on a lower scale.

When a part work hardens during machining, its surface becomes a shiny glaze and appears slippery. The machined part can even take on the same hardness as the cutting tool.