Metalworking fluids assist with chip evacuation and reduce friction and heat to help extend tool life and improve surface finishes during machining operations. The choice between water-dilutable fluids or straight oil depends on the cooling and lubrication performance requirements for different materials, tooling and machining processes combined with environmental factors, including operator acceptance, safety and disposal.
Water-Soluble Fluids
Water-dilutable metalworking fluids are a concentrate of mineral oil or synthetic fluids, emulsifiers and additives designed to control wear, corrosion, foam and microbial growth. Soluble metalworking fluids are mixed with water to form an emulsion, using different ratios depending on the fluid and the metalworking process.
Performance is highly dependent on the application, formulation, and ongoing fluid maintenance. Regular concentration monitoring can extend fluid life and limit microbial fungal and bacteria growth, which are heavily influenced by water quality, coolant quality and tramp oils that all contain food sources. Synthetic products are more likely to experience fungal growth
• Soluble Oils are water-dilutable concentrates composed of mineral oil and emulsifiers, often enhanced with extreme-pressure and antifoam additives. They provide moderate cooling with excellent lubricity for friction reduction and tool protection in moderate- to heavy-duty metalworking applications.
• Semi-Synthetic Fluids are a microemulsion that blends soluble oils with synthetic components to gain the benefits of both mineral oils and synthetic fluids in delivering balanced lubrication and cooling. Performance characteristics are dependent on formulation, and semi-synthetics are a good choice for moderate- to heavy-duty mixed-machining applications where both cooling and lubrication are required.
• Synthetic Fluids are fully water-soluble, oil-free fluids with superior cooling capability, excellent resistance to bacterial growth, cleaner operation and lower disposal cost. However, they have lower lubricity and extreme-pressure performance compared to oil-based fluids and are best for heat control in precision grinding and high-speed machining.
Straight Oil
Straight oils are undiluted mineral or synthetic oils with extreme-pressure additives that provide maximum lubricity and load-carrying capacity. Straight oils provide limited cooling and are ideal for high-load, high-pressure and precision machining applications, including deep-hole drilling, broaching and tapping.
Choosing the Right Fluid
Modern metalworking fluid technology is highly adaptable to suit many different needs. Choosing the right fluid depends on a variety of factors, including the type of cutting tool, workpiece material, machining operation, speed, feed and cut depth, water quality, sump and filtration, downstream operations, maintenance and disposal costs, and operator preferences:
• Material Type: Considerations include water accelerating oxidation, rust and corrosion and active sulfur staining aluminum.
• Machining Process: Consider whether the application requires more cooling due to speed and friction or more lubrication due to extreme pressure or hardened materials.
• Tool Life and Performance: Consider optimizing fluid selection by application to extend tool life and enhance product quality.
• Environmental Factors: Consider operator safety and acceptance, and compliance with environmental and disposal regulations.
• Maintenance: Considering the complete fluid life cycle, proper fluid maintenance is essential for maximizing tool life and machining efficiency and maintaining a safe working environment.
AMSOIL Industrial provides a wide range of high-quality metalworking fluids specifically engineered to maximize machining performance, workpiece quality and operational efficiency in any metalworking environment. Experienced AMSOIL Industrial Application Engineers work directly with your team to understand your processes and identify the best products and solutions to maximize your productivity and profitability.
Download our Cutting & Grinding Oil quick-reference chart for a quick summary of metalworking fluid applications or contact us today to learn more.