Metalworking Fluids and Lubricants 101
What are Metalworking Fluids?
Metalworking fluids (MWFs) are products that are used to optimize the metalworking process. They play a critical role in the metal removal and metal forming processes. When a metal is in the cutting or forming phase, MWFs, such as lubricants, reduce the heat and friction between the cutting tool and the machined part. This helps prevent burning and smoking by removing the fines, chips and swarfs from the tool being used.
In this informative guide, we present an overview of metalworking fluids and lubricants, including: common types, their functions, benefits, composition, storage and safety regulations. As a global distributor for metal manufacturers, we at Ravago Chemicals North America are proud to partner with leading suppliers in the industry to bring innovative, technical solutions for optimal metalworking and manufacturing.
Types of Metalworking Fluids
- Metalworking Fluids used for metal removal processes are known as cutting and grinding fluids.
- Metalworking Fluids used for metal forming processes are called metal forming fluids
Within these two types of metalworking fluids are classes of fluids with many different components and additives.
- Straight Oils – also known as “neat” or “cutting” oils, are usually made from mineral (petroleum), marine, animal, vegetable or synthetic oils. These oils are “severely solvent refined” or “severely hydrotreated”. These are refining treatments that help reduce the amount of polynuclear aromatic hydrocarbons (PAHs). These oils are not diluted with water, but other additives are often present.
- Soluble Oils (emulsifiable oils) – contain 30 to 85 percent severely refined petroleum oils, and emulsifiers to disperse the oil in water.
- Semi-synthetic fluids – contain between 5 to 30 percent severely refined petroleum oils, 30 to 50 percent water and a variety of additives.
- Synthetic fluids – are fluids that use detergent-like components and other additives to help “wet” the metal workpiece.
While each class above varies in composition, each contains a combination of additives such as:
- Sulphurized or chlorinated compounds
- Corrosion inhibitors (e.g., calcium sulfonate, sodium sulfonates, fatty acid soaps, amines, boric acid)
- Extreme pressure additives (e.g., sulfurized fatty materials, chlorinated paraffins, phosphorus derivatives)
- Anti-mist agents (e.g., polyisobutylene polymer)
- Anti-weld agents
- Emulsifiers (e.g., triethanolamine, sodium petroleum sulphonates, salts of fatty acids and non-ionic surfactants)
- Biocides (e.g., triazine compounds, oxazolidine compounds)
Functions of MWFs
Not all MWFs serve the same purpose in metalworking. There are several different ingredients and compositions on the market based on the function. The following list describes some of the main functions for MWFs:
- Lubrication – reduces the friction and adhesion between the tool or die and the metal
- Cooling – reduces and removes the heat generated by the metalworking process
- Corrosion Protections – protect the metal piece and the machine from corrosion
- Chip Removal – flushes metal chips away from the cutting zone
What are the Benefits of MWFs
MWFs play a critical role in ensuring the machining process is smooth and accurate by regulating the temperature created between the tool and the metallic piece. Other benefits to the metalworking process include the following:
- Extend Tool Life
- Encourage Accurate and Precise Dimension Control
- Improve Surface Finish
- Reduce Power Consumption
What Influences the Chemist Process
When selecting or developing a metalworking fluid for an application, chemists usually take two processes into consideration: primary selection and secondary selection.
Primary Selection considers the safety and industry standards established within a country or region. This includes: regulations, waste treatment, pre-post processes and water quality. Furthermore, the type of operation, type of metallic material and tools used also influence the development of a metalworking fluid. These considerations will ensure that the optimal fluids, additives and other enhancements will work according to the manufacturing site’s needs.
Secondary Selection delves into the properties of the metal material more. Lab tests and development take into account the following: lubricity, surface finish, dimension tolerates, detergency and coolants.
Guidelines for Storing MWFs
Storing MWFs properly in the workspace is crucial to maintaining the integrity of the fluids and the safety of the metal workers.
Generally, MWFs are delivered via pump to the point of operation and sprayed, dripped or flooded over the tool or workpiece. This application creates airborne mists that pose a health risk. Metal manufacturing facilities must follow specific OSHA guidelines for containing MWFs. This includes: proper ventilation, PPE for workers, enclosures around the workspace that minimize exposure, and appropriate fluid selection with the least amount of toxins.
MWFs can change during storage, which taints the overall composition, effectiveness and safety of the fluid. Nitrosamines can form in water-based MWFs while the fluid is stored for long periods of time. These are a big concern as they are classified as carcinogens. Another primary concern is the growth of bacteria and fungi in water-based MWFs. The bacteria degrade the emulsions and change the properties of the MWFs. Biocides are often added to offset the amount of microbial growth, but they also have hazardous properties. Other sources of microbial growth include “tramp” oil – oil used for machine lubrication (hydraulic oil, gear box oil, etc). Likewise, it is important to ensure small metal or alloy objects do not contaminate the MWFs.
OSHA guidelines recommend having a fluid management program in place to address MWF contamination and purity. This ensures periodic assessment of additives, testing for performance and optimal shape as well as establishing health and safety standards for employees.
Our Metalworking Suppliers
**Dover products are available in the following states: Illinois, Indiana, and Wisconsin.
Ravago Chemicals North America. Technically Focused. Solutions Driven.
Our ties to the global supply chain of Metalworking Fluids and Lubricants allow us to provide the best-in-class service and products to our customers in the metal manufacturing industry. We support our customers with their formulation needs to encourage innovative advancements and a material that suits the project. Although we have a global outreach, we provide regional distribution channels throughout the North American market. Fast and flexible service with expert technical knowledge allows us to partner with our customers to realize their business goals.
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