In the context of metalworking, solutions like cutting fluids and coolants see frequent use.
While both are used to improve machining processes onsite, their primary functions are different due to the unique benefits they supply.
Getting a grasp on the differences between cutting fluid and coolant is key for firms that depend on industrial equipment, as the proper product choice can enhance mechanical performance, reduce wear and cut operating costs. Here, we look at coolant and cutting oil in detail, how they are employed and their key differences to help users decide which option they require for applications.
What is coolant and how is it used?
Coolant is defined as a fluid utilised in multiple machining processes like turning, milling and grinding, and is primarily used for heat removal. It can help extend tool life, but it also enhances the surface finish of the workpiece produced.
As their name indicates, coolants reduce heat building up but also perform several other roles. They lubricate, defend against corrosion and flush away unwanted debris within the cutting zone. These specially engineered fluids come in a wide range of different formulas but mainly fall into four categories: straight oils, synthetic fluids, semi-synthetic fluids and soluble oils. Each coolant type has certain characteristics that suit specific metal machining applications.
What are cutting fluids and how are they used?
Although coolants lubricate, their main role is to lower heat levels – but cutting fluids are designed to provide lubrication and cooling simultaneously. Cutting fluids are a specific type of coolant and are designed for metalworking processes like stamping and machining, among others.
Available from leading manufacturers like Kluber and Fuchs, cutting fluid is sometimes called “straight oil” or “neat oil”. At work, it’s a refined mineral oil that can function as a sole lubrication solution in machining processes.
Cutting oils are deployed undiluted, supplying special advantages that can meet machining requirements. Cutting fluids predominantly consist of base oils but these can be synthetic, semi-synthetic or just mineral oil. However, they are also infused with additives to enhance their performance.
Common additives in cutting fluids include extreme pressure (EP), anti-wear and anti-corrosion. This makes them effective at reducing wear and friction in between the workpiece and the tool. They promote prolonged tool life and improved surface quality of parts machined onsite.
Exceptionally versatile, these fluids are employed in a wide array of machining processes like drilling, milling and turning and see frequent use in high-pressure environments that require products with powerful lubricating properties.
Comparing coolant and cutting fluid
To maximise machining processes, it’s key to know how coolants and cutting fluids differ.
Main function
The core function of a coolant is to manage heat levels, cooling both the workpiece and cutting zone. Its secondary functions involve lubrication, corrosion protection and flushing debris from the work area.
While cutting oils also cool, their main job is to lubricate and decrease friction, wear and tear between the workpiece and cutting tool. They create a robust lubricating film that can improve tool life and workpiece surface finish.
Formulation
The composition of coolants is usually water-based. Types include soluble oils, synthetic fluids, straight or neat oils and semi-synthetic fluids. Many coolants must be diluted with water and often contain additives to help cool and lubricate. In contrast, cutting oil isn’t diluted and is mainly made up of base oils with various additives enhancing its performance.
Operating conditions
Coolant is applicable for a diverse array of machining operations like grinding, turning and milling, and is vital for processes where managing heat levels is critical. Cutting fluids see use in high-pressure environments like heavy-duty machining. It’s especially useful in processes such as stamping and drilling.
Lubricating and cooling
Both products lubricate and cool cutting zones and workpieces. However, coolants are designed to manage heat, but with less emphasis on lubrication, and cutting oils offer enhanced lubrication because they are undiluted and are less focused on cooling.
Additives packages
Coolant additives are designed to enhance cooling and lubricant properties but also to prevent unwanted microbial growth. However, cutting fluids have additives to help them work in challenging operating conditions like anti-wear, anti-corrosion and extreme pressure agents.
Fluid maintenance
Finally, coolant and cutting fluids require different maintenance schedules. As it’s usually diluted, in use, coolant needs routine maintenance, so that concentration and pH levels are correct and that microbial contamination is monitored. Undiluted, cutting oil maintenance is less frequent, but it still needs checks to keep it contaminant free.
