Extreme pressure (EP) additives are additives used in metalworking fluids that provide enhanced lubrication and protection during high-pressure and high-load machining operations. These additives are specifically designed to form a protective film on metal surfaces, reducing friction, wear and heat generation under extreme operating conditions.
EP additives usually contain compounds such as sulfur, phosphorus and chlorine. These additives chemically react with the metal surface to form a thin film that acts as a lubrication barrier. The film helps prevent metal-to-metal contact and reduces friction and wear, even under extreme pressure and high temperature conditions.
In metalworking fluids, extreme pressure additives are commonly used in cutting oils, stamping and drawing compounds, and lubricants used in metal forming processes. These additives provide vital lubrication and protection to metal surfaces during operations such as drilling, tapping, milling and turning, where cutting tools and workpieces are subject to extreme forces and pressures.
Using extreme pressure additives in metalworking fluids can provide a variety of benefits, including:
- Extended tool life: EP additives reduce friction and wear on cutting tools, extending their service life and reducing the need for frequent tool changes.
- Enhanced surface finish: The protective film formed by EP additives helps maintain the integrity of the workpiece surface, resulting in better surface finish and dimensional accuracy.
- Reduces heat: EP additives dissipate heat generated during machining operations, preventing overheating and thermal damage to tools and workpieces.
- Increased productivity: By reducing tool wear and heat generation, EP additives increase cutting efficiency and reduce downtime due to tool changes and maintenance.
Of note, chlorine-containing EP additives have come under intense scrutiny for their potential environmental and health effects. Therefore, there is a growing trend to use chlorine-free extreme pressure additives or alternative lubrication technologies in metalworking fluids.