The role of cutting fluid in prolonging the functional life of tools in metalworking

In metalworking, cutting fluid plays a vital role in providing lubrication and decreasing the amount of heat generated. However, the importance of cutting oil is significantly more than you may imagine. The fluid is a performance-enhancing agent in machining. It extends the life of the workpiece and tool by reducing friction between them and improving their surface quality.Cutting fluid is available in various variants based on the tool's metal type. Its selection criteria include machine type and operation mode, i.e., drilling, turning, etc. The tool specifications, plant processes, and chemical reaction-related stipulations can also be factored in. The right kind of fluid empowers you to make machine performance optimum and cost-effective.

The role of cutting fluid in extending a tool's life

Cutting fluid offers numerous avenues for increasing tool life. The major ways the fluid improves machining efficiency and longevity have been discussed below.

1. Removes chips from the chip zone

Chips are formed during metalworking when parts of the material being worked upon start detaching from the surface due to extreme pressure applied by the cutting edge. When the cutting speed is high, the rate of chip generation is also high. Resultantly, the cutting zone temperature rises considerably, hastening the tool-wearing process.

Cutting fluid is applied right to the cutting zone closest to the area of chip formation at high pressure. This flushing process removes the accumulating chips from the zone that experiences maximum temperature. As the chip zone is cooled, further wearing down of the tool is prevented.

2.  Reduces pressure on the cutting tool through extreme pressure additives

Extreme pressure additives are added to soluble cutting oil to absorb the cutting force, reducing the cutting tool's pressure. The additives create a lubricating film on the workpiece’s surface. As a result, cutting fluid delivery is facilitated under hostile conditions characterised by high pressure and temperature. Additives boost the lubrication and cooling functions of the fluid.

Additives trigger a chemical reaction with the surface of the metal to form the reactive film. Some additives create a protective film through thermal degradation during metalworking. As the wearing-down process of the tools is controlled, the final product measures up to the tolerance limits. Spindle vibration is minimised, which does away with the need for frequent repairing of machines.

3.Protects machinery from corrosion

Machining tools are constructed from ferrous metals that are prone to corrosion when exposed to moisture or oxygenated air. Carbon steel, stainless or mild steel, and cast or wrought iron are used for making cutting tools. Cutting fluid has a pH in the range of 8.8 to 9.6, which prevents the corrosion of machining metals.

The ingredients of the cutting fluid are carefully balanced to prevent the end product from becoming extremely alkaline or acidic. As a result, it prevents the frequent maintenance of tools even if they are constructed from different metals. Elastomers’ flexibility is not lost, prolonging the life of the tools. A good quality cutting fluid can increase the functional duration of tools by more than 200%.

4.  Limits metal-to-metal contact

The viscosity level of cutting fluid is adequately determined to ensure its thorough penetration from tool to workpiece at the contact point. The liquid forms a cushioning layer between the workpiece and the tool, limiting the contact. As interaction is reduced maximally, the wearing rate decreases significantly, maintaining the surface integrity of tools. The finished piece also gets a smoother surface, free of defects, scratches, and deformities.

In operations involving the making of the hole where outward delivery of fluid is restricted, fluid is used through the internal conduits of the spindle. It further regulates the cutting temperature and alleviates frictional contact. Thus, thermo-mechanical wear is reduced.

5. Reduces residue formation

Even under high temperature and pressure, a good quality cutting fluid suffers from negligible quality deterioration because the fluid is kept clean and free from contaminants. As the consistency is smooth and the additives are amalgamated in the right proportion, minimal depletion of additives occurs due to the cutting action. Any 'drag out' loss is compensated by adding new fluid. Smooth consistency, regular top-up of oil to prevent thickening, and almost zero contamination prevent residue formation in significant quantities.

Any residue left behind gets removed spontaneously and is easy to clean even if it remains on the surface for long.

6. Decreases energy cost

You can significantly reduce your workshop’s energy cost by using proper cutting fluid. The film layer formed between the tool and the workpiece, and the reducing corrosion rate contributes to this. The wear rate of the tool follows a consistent pattern that makes it predictable. As a result, you can take proactive measures for inefficient tool replacement once it has outlived its life.

Tripping of in-built sensors is prevented to a great extent because of the stellar performance of the cutting tool. You don’t have to worry about the cutting tool failing while a job is in progress. Condition monitoring can be done effectively, improving the lifecycle and reliability of tools.

Conclusion

The importance of cutting fluid in increasing the life of machining tools is undeniable. Extreme pressure additives in cutting fluids play a critical role in improving tools' functional life and performance. However, the cutting tools and machining parts can sustain substantial damage if suitable fluid is not used. It can further compromise the efficiency of metalwork.

All cutting fluid variants available in the market are not the same. You need to rely on the expertise of a fluid supplier for maintaining optimum parameters in the cutting fluid to meet the unique requirements of your metalwork.

Castrol, for instance, offers insightful and extensive support in choosing the appropriate fluid product that can help customers reap rich dividends. Customers can also benefit from Castrol’s excellent technical support service. Maintaining optimum metalwork productivity and extending tool life becomes more manageable with Castrol’s qualitative support.