Introduction to Metal Cutting Fluids 221

"Introduction to Metal Cutting Fluids" provides an overview of the use of cutting fluids in machining operations, including basic fluid safety and maintenance. Appropriate cutting fluid selection depends on the specific cutting operation and workpiece material, among other factors. Basic types of cutting fluids include various combinations of oils, water, and chemicals. Each type is classified by its contents. After explaining the basic function of cutting fluid, the class describes each category of fluid and its benefits and drawbacks.

Appropriate cutting fluid use and maintenance are key factors in the success of a cutting operation. Proper cutting fluid application can prolong tool life and improve finished part quality, reducing scrap and tool cost. Awareness of cutting fluid hazards and maintenance helps increase workplace safety and reduce fluid costs. After taking this class, users will be able to identify the common types of cutting fluids and describe their optimal use.

Class Details

Class Name:
Introduction to Metal Cutting Fluids 221
Version:
2.0
Difficulty:
Intermediate
Number of Lessons:
24
Related 1.0 Class:
Cutting Fluids 210

Class Outline

  • Metal Cutting Fluids
  • Heat and Cooling
  • Heating and Cooling in Action
  • Friction and Lubrication
  • The Workpiece and Machining
  • Cutting Fluid Basics Review
  • Types of Cutting Fluids
  • Inactive Cutting Oils
  • Active Cutting Oils
  • Emulsifiable Oils
  • Chemical Fluids
  • Semi-Chemical Fluids
  • Cutting Fluid Types Review
  • Selecting a Cutting Fluid
  • Delivering a Cutting Fluid
  • Cutting Fluid Delivery Methods
  • Oil Maintenance
  • The Importance of Water Properties
  • Cutting Fluid Essentials Review
  • The Importance of Fluid Concentration
  • Fluid Cleaning, Maintenance, and Disposal
  • Health and Safety
  • Minimal Fluid Cutting
  • Final Review

Objectives

  • Describe reasons for using cutting fluids.
  • Describe how heat is generated during cutting and how cutting fluids affect heat.
  • Describe the role of lubrication during machining.
  • Describe how tensile strength and severe machining impact cutting.
  • Identify the major categories of cutting fluids.
  • Describe inactive cutting oils and their uses.
  • Describe active cutting oils and their uses.
  • Describe emulsifiable oils and their uses.
  • Describe chemical fluids and their uses.
  • Describe semi-chemical fluids and their uses.
  • Identify variables that influence cutting fluid selection.
  • Describe how cutting fluids are delivered to the cutting area.
  • Identify common oil maintenance considerations.
  • Describe the importance of water quality and pH level for miscible cutting fluids.
  • Describe how fluid concentration impacts fluid performance.
  • Identify fluid cleaning and maintenance methods and disposal concerns.
  • Describe health and safety issues related to cutting fluid use.
  • Describe the process of machining with minimal or no cutting fluid.

Job Roles

Certifications

NIMS
  • CNC Lathe Operations
  • CNC Milling Operations
  • CNC Milling Programming, Setup, & Operation
  • CNC Turning Programming, Setup, & Operation
  • Drill Press I
  • Grinding I
  • Measurement, Materials, & Safety I
  • Milling I
  • Turning Operations: Turning Chucking Skills

Glossary

Vocabulary Term Definition
acidity The state of having a pH value below 7. Vinegar and lemon juice are examples of acidic substances.
acidity The state of having a pH value below 7. Vinegar and lemon juice are examples of substances that have acidity.
active oils An oil that releases sulfur during machining to lubricate the cutting tool, workpiece, and chips. Active oils are used in applications where the chips are likely to crowd, such as in threading.
additives A substance added to a cutting fluid to improve lubrication, cooling, or both during machining. Common additives include chlorine, sulfur, defoamers, and phosphates.
alkalinity The state of having a pH value above 7. Soap and oil are examples of substances that have alkalinity.
alloys A metal with purposefully added elements to enhance its mechanical and physical properties. Alloys are often named after the base metals of which they are primarily composed.
aluminum A silver-white metal that is soft, light, and thermally conductive. Aluminum has high ductility, which can cause extreme cutting forces during machining that require a cutting fluid with good lubrication.
animal oil A natural oil derived from the fat of animals. Animal oils are often used to improve the lubrication properties of straight oil.
atomic structures The organization of atoms in a substance. Atomic structures determine the physical and mechanical characteristics of a substance.
atoms The smallest distinguishable unit of an element. Atoms combine to form molecules.
bacteria Microorganisms that may be harmful to inhale or ingest. Bacteria growth in cutting fluids is a sign of contamination and must be controlled.
biocides A substance that kills germs. Biocides are added to cutting fluids to prevent biological or fungal contamination.
boundary lubrication Lubrication that is provided between the cutting tool and the workpiece. Boundary lubrication improves the finished quality of a part and extends the working life of a tool.
Brix scale A system used for measuring the concentration of a substance that has been mixed with water. The Brix scale is used in conjunction with a refractometer to determine the concentrate of a cutting fluid.
broaching The use of a cutting tool with teeth similar to a file that is used to change the shape or dimensions of a hole. Broaching is usually performed with sulfochlorinated mineral oils since they prevent pressure welds.
BUE Built-up edge. The unwanted, rough edge on a cutting tool created when pieces of the workpiece pressure weld on the tool edge during cutting. BUE can reduce the quality of a finished cut.
built-up edges BUE. The unwanted, rough edge on a cutting tool created when pieces of the workpiece pressure weld on the tool edge during cutting. Built-up edges can reduce the quality of the finished cut.
calcium A soft, gray, alkaline metal found abundantly in nature. Calcium is present in many water sources and can cause water hardness.
carbon dioxide CO². A heavy, colorless, odorless gas. Carbon dioxide can be used with compressed air to blow chips away and cool metals during cutting procedures.
cast iron An alloy of iron, carbon, and silicon that contains at least 2.0% carbon. Cast iron is always cut without the use of cutting fluid in manufacturing operations.
central system A large reservoir and distribution system that supplies cutting fluid to several machine tools. Central systems are usually used to facilitate the cleaning of large amounts of cutting fluid.
centrifuges Machines that separate elements of a solution based on their density. Centrifuges are used to clean cutting fluid by separating debris and tramp oil from the fluid.
centripetal force A force that makes a body follow a curved path. Centripetal force causes a fluid to separate into its various parts based on the density of each part.
chemical fluid A cutting fluid made from water and chemicals, such as nitrites and phosphates. Chemical fluids, also known as synthetic fluids, are primarily used for their ability to cool.
chemical fluids A cutting fluid made from water and chemicals, such as nitrites and phosphates. Chemical fluids, also known as synthetic fluids, are primarily used for their ability to cool.
chipping An irregular breakdown of the surface of a workpiece or cutting tool caused by small fragments fracturing off during the machining operation. Excessive chipping can make a part unusable and reduce the working life of a cutting tool.
chips An unwanted piece of metal that is removed from a workpiece. Chips are formed when a tool cuts or grinds metal.
chlorine A light, abundant chemical substance that is toxic in gaseous form. In certain chemical configurations, chlorine serves as lubricant when present in metal cutting fluids.
coating treatments A procedure where a finishing product of some kind is applied to the surface of a cutting tool. Coating treatments have a range of beneficial attributes, such as reducing friction and preventing pressure welding.
compressed air Air that has been squeezed into a small space and can be released at high pressure. Compressed air is used in a number of cutting fluid applications, such as gases, spray mist, and minimum-quantity lubrication.
concentrate The chemical mixture that is diluted with water to create a suitable cutting fluid. Concentrate must be checked regularly to ensure optimal cutting fluid performance.
concentrations The measure of the ratio of coolant to water found in the coolant sump or central system. Cutting fluids that work at low concentrations tend to be less expensive.
contaminants Any foreign substance that may cause a loss of efficiency or a breakdown in a fluid system. Contaminants must be cleaned from a cutting fluid through the use of a skimmer, centrifuge, or similar device.
contamination The presence of any unwanted substances in a fluid system. Cutting fluid contamination can be controlled through fluid maintenance.
cool The process of removing heat from an area. Cutting fluids cool a cutting operation by absorbing heat caused by friction and carrying it away from the cutting area.
coolant sump The tank on a machine tool that holds and pumps cutting fluid. A coolant sump should be regularly cleaned of contamination such as tramp oil or build-up from hard water residue.
coolant sump The tank on a machine tool that holds and pumps cutting fluid. A coolant sump should regularly be cleaned of contamination such as tramp oil or build-up from hard water residue.
coolants A fluid used to cool or lubricate a metal cutting process. Coolants, also known as cutting fluids, can be oil- or water-based liquids, gases, or pastes.
copper A reddish metal that is very ductile, thermally and electrically conductive, and corrosion resistant. Copper requires good lubrication when cutting because of its ductility.
copper alloys A metal made from copper purposefully combined with another element to enhance its mechanical and physical properties. Copper alloys, such as brass and bronze, have low tensile strength.
corrosion resistance The ability of a material to resist deterioration and chemical breakdown due to surface exposure in a particular environment. Corrosion resistance in machined parts can be improved through the use of cutting fluids.
cutting fluids A fluid used to cool or lubricate a metal cutting process. Cutting fluids, also known as coolants, can be oil- or water-based liquids, gases, or pastes.
cutting forces A force generated by the motion of the cutting tool and the resistance of a workpiece. Cutting forces can cause issues such as chip welding or poor surface finish if they are not reduced through the use of cutting fluids.
cutting functions An issue directly affecting the machining process. Cutting functions include chip removal, surface finish, and tool service life.
cutting oils A cutting fluid that is based on mineral oil and contains no water. Cutting oils provide excellent lubrication but less cooling.
cutting oils A cutting fluid that is based on mineral oil and contains no water. Cutting oils provided excellent lubrication but less cooling.
cutting speed The measurement of how fast the cutting tool moves in relation to the workpiece. Cutting speed helps determine the type, amount, and application of cutting fluid necessary for a given cutting operation.
cutting tool A device made of hard, tough material that is used to remove metal by creating chips. A cutting tool can be protected from premature wear through the use of cutting fluid.
debris An unwanted fragment of material. Debris can contaminate cutting fluid and reduce its efficiency.
defoamers An additive used in cutting fluids to prevent the development of bubbles in the fluid. Defoamers improve the cooling ability of a cutting fluid.
dermatitis A red, itchy rash that appears on the skin. Dermatitis is a common issue caused by skin exposure to cutting fluids and can lead to permanent scarring and skin disfiguration.
detergency The ability to remove unwanted liquids or solids from the surface of a material. Cutting fluids with high detergency can keep workpieces from staining, but they also cause skin irritation after repeated exposure.
dimensions The desired measurements of a finished part. Dimensions are typically indicated by length, width, and height.
dissolved Incorporated into a liquid. Additives are dissolved in cutting fluids to improve their lubricating and cooling properties, among other attributes.
dry machining The process of cutting metal without using cutting fluid. Dry machining eliminates the costs associated with purchasing, maintaining, and disposing cutting fluid.
dry machining The process of metal cutting without using fluid for lubrication or cooling. Sometimes minimum quantity lubrication (MQL) is referred to as dry machining because the mist of air and oil burns off or evaporates during cutting.
emulsifiable oils A cutting fluid that is composed of oil, emulsifiers, water, and other additives. Emulsifiable oils, also konwn as soluble oils, are obtained as a concentrate, which is then mixed with water.
emulsifiers A substance that allows small droplets of one liquid to be suspended in another liquid. Emulsifiers allow oil and water to mix to form a stable solution.
Environmental Protection Agency EPA. The federal government agency established by the United States to establish a cleaner, healthier environment. The Environmental Protection Agency is responsible for research, monitoring, standard setting, and enforcement activities to ensure environmental protection.
extreme pressure additives EP additives. Chemicals added to cutting fluids to enhance cutting fluid performance under high temperature and pressure conditions. Extreme pressure additives include sulfur and chlorine.
extreme pressure fluids A water-based cutting fluid that has chemicals added to improve its lubrication properties. Extreme pressure fluids often contain additives like chlorine or phosphorous.
extreme pressure soluble oils A cutting fluid that contains additional compounds to increase lubrication under extreme cutting conditions. Extreme pressure soluble oils are made by adding chemicals like sulfur or chlorine to soluble oils.
fatty oil A group of naturally occurring oils including some types of animal, vegetable, or marine oils, used as cutting fluids or as additives. Fatty oils increase lubrication when used with mineral oils.
ferrous A material in which iron is the main ingredient. Ferrous metals can rust when exposed to acidic fluids.
film A thin layer or sheet. A film of cutting fluid, particularly when using oil, forms between the workpiece and cutting tool to prevent direct contact between the two.
film lubrication A friction reducing process where there is no direct contact between the cutting tool and workpiece. Film lubrication provides excellent protection for a workpiece and can extend the working life of a tool.
filter A screen used for limiting contamination by trapping and separating particulate matter. A filter can be used to strain out debris and other contaminants from cutting fluids.
flood method A method of fluid delivery in which the cutting fluid is routed through nozzles and completely covers the workpiece and the cutting tool. The flood method is the most commonly used cutting fluid delivery system.
foaming The action of frothy bubbles forming in the fluid due to excess air. Foaming reduces fluid contact with the tool and workpiece, reducing cutting fluid efficiency.
friction A force that resists the movement of two objects sliding against each other. Friction causes heat to form in the areas where the objects make contact.
gases A fluid without a fixed volume that has the ability to flow and fill the space it occupies. Gases are sometimes used as metal cutting fluids.
graphite A soft, black carbon-based material that can be used as a lubricant. Graphite can be placed on the surface of a workpiece or incorporated into the tool itself.
grinding The use of an abrasive to cut the surface of a workpiece and change its shape. Grinding applications often require the use of a semi-chemical cutting fluid.
grinding wheel A tool made by bonding abrasive grit together and forming them into a circular shape. A grinding wheel is sometimes made with graphite mixed in with the abrasive grit to provide lubrication.
hard The degree of a material's resistance to penetration. Hard metals require cutting fluids with excellent cooling properties when being machined.
heat The accumulation of elevated temperature. Heat is often the result of friction.
heavy-duty machining A machining process that takes place at high speeds and heavy feeds. Heavy duty machining requires cutting fluids that provide good lubrication and cooling.
high-pressure, high-volume method HPHV method. A method of fluid delivery in which fluid is forced through a nozzle at high speeds. The high-pressure, high-volume method is used in severe machining applications that require particularly effective cooling and lubrication.
high-speed cutting Any metal cutting operation that takes place at a particularly rapid pace. High-speed cutting operations usually require cutting fluids with good cooling properties.
HPHV method High-pressure, high-volume method. A method of fluid delivery in which fluid is forced through a nozzle at high speeds. The HPHV method is used in severe machining applications that require particularly effective cooling and lubrication.
inactive oils A cutting oil that releases very little lubricating sulfur during machining. Inactive oils are mostly used for light-duty machining on nonferrous metals.
insert A removable, geometric cutting bit that has multiple cutting edges. An insert is often used as the metal removal tool in metal cutting operations.
light-duty machining The machining of easily cut metals at low speeds and light feeds. Light-duty machining usually requires metal cutting fluids that lubricate, such as straight cutting oils, rather than fluids that cool.
low-carbon steel A plain carbon steel that contains less than 0.30% carbon. Low-carbon steel generally has high tensile strength.
lubrication The reduction of friction between two surfaces in relative motion through the use of a specialized substance. Cutting fluids provide lubrication in metal cutting applications.
machine tool A power driven piece of metalworking equipment for cutting or forming metal. Machine tools are often lubricated with oils that can contaminate a cutting fluid system.
machining The process of removing material to form a specified object. Traditional machining methods, such as milling, turning, and drilling, remove metal using cutting tools.
magnesium A grayish white, extremely light metal that is also brittle and has poor wear resistance. Magnesium is found in many water sources and contributes to water hardness.
magnetic cleaners A device that attracts ferrous materials through magnetism. Magnetic cleaners can remove ferrous debris from cutting fluid to keep the fluids functioning optimally.
make-up rate The additional cutting fluid concentrate needed to maintain the correct fluid concentration. A make-up rate will vary depending on concentrate readings taken by a refractometer.
marine oils A natural oil derived from the fat of marine animals. Marine oil can improve lubrication when added to straight oil.
medium-duty machining The machining of metals at moderate speeds and feeds. Medium-duty machining processes include shaping, facing, and boring.
metal A naturally occurring material with high electric and thermal conductivity, luster, density, and strength. Examples of metal include copper, iron, nickel, and lead.
metal cutting A machining process that uses a tool to remove metal from a workpiece. Metal cutting processes include drilling, turning, and milling.
metalworking fluids MWF. The collective grouping of the most common coolant fluids used in metal cutting. Metalworking fluids include cutting oils, soluble oils, and chemical fluids.
milling A machining operation that uses a multi-point horizontal or vertical cutter to remove metal from the surface of a workpiece. Milling operations often require the use of cutting fluids with excellent cooling properties.
mills A multi-point machine tool used to either horizontally or vertically remove metal from the surface of a workpiece. Mills often require the use of ring-distributed cutting fluids during operation.
mineral oils A light oil that is a byproduct of petroleum distillation. Mineral oil is used as a cutting fluid to provide both lubrication and cooling though it provides better lubrication.
minimum quantity lubrication MQL. A form of cutting fluid delivery where a small amount of lubricating oil is misted over the face of the cutting tool. Minimum quantity lubrication can prevent the thermal cracking sometimes caused using other types of fluid delivery.
nitrites An alkaline substance derived from nitrous acid. Nitrites are used as an additive in chemical fluids to prevent rusting of the workpiece.
nitrogen An inert, odorless gas that naturally exists in the atmosphere. Compressed nitrogen can be used to cool workpieces and cutting tools during metal cutting operations.
noncutting functions An issue that affects the general workplace. Noncutting functions include worker safety, disposability, and residue formation.
nonferrous A material that does not contain a significant amount of iron. Nonferrous metals include aluminum and copper.
Occupational Safety and Health Administration OSHA. A government agency that sets the standards for working conditions in the United States. The Occupational Safety and Health Administration ensures that operators work in safe and healthy environments.
parts per million ppm. A measurement that assesses how many parts of one substance are present in one million parts of another substance. Parts per million is a common measurement when assessing water hardness.
pastes A lubricant with a thick, sticky consistency. Pastes, also known as solid lubricants, can be mixed in with other materials or spread on a surface of an object, such as the surface of a cutting tool.
personal protective equipment PPE. Any clothing or device worn to minimize exposure to hazards and prevent injury. Personal protective equipment for operations using cutting fluids may include safety goggles, gloves, and respirators.
pH A measure of the acidity or alkalinity of a substance. A pH value below 7 is acidic, and a pH value above 7 is alkaline.
pH meter An instrument used to measure acidity or alkalinity. A pH meter is essential to help maintain proper functioning of metal cutting fluids.
phosphates An inorganic chemical salt of phosphoric acid. Phosphates are used in chemical fluids to soften the water.
plain fluids A semi-chemical fluid that contains no additives. Plain fluids provide a good balance of cooling and lubrication.
polymer A material made of very large molecules. Synthetic polymer additives are used in cutting fluids to improve their effectiveness.
pressure The exertion of force upon a fluid. Changes in pressure can affect the efficiency of a cutting fluid.
pressure weld An area where a chip attaches to the cutting tool or workpiece due to high temperatures and pressures involved in metal cutting. A pressure weld can result in surface defects such as chipping.
rancid A substance that has decomposed and developed an unpleasant odor. Rancid oils also tend to promote bacterial growth, which can be dangerous for any machine operators who handle or work with the oil.
rancidity Having an unpleasant odor as a result of decomposition. Rancidity lowers cutting fluid performance and poses an increased safety risk for machine operators.
react When two materials or substances interact. When metal cutting without cutting fluid, newly exposed surfaces of a workpiece can react with the air to form rust or other compounds that affect the quality of the finished part.
refractometer An optical instrument used to measure the chemical or oil concentration in a miscible cutting fluid. A refractometer uses a Brix scale to assess the amount of concentrate in a cutting fluid.
residue A substance deposited or left behind by a reaction or event. Residue can be controlled through the selection of the proper cutting fluid.
respirators A breathing device worn to prevent inhalation of particles and hazardous substances. Respirators may purify air from the environment or supply air to the wearer.
respiratory Concerning the organs involved in breathing air. Respiratory organs include the nose, esophagus, and lungs.
ring-distributor method A fluid delivery method that routes fluid through small holes in a tube around the cutting tool. The ring-distributor method is often used with round cutting tools, such as mills.
rust A general term for iron oxide. Rust is a reddish-brown substance caused by a ferrous metal's reaction with moisture and oxygen.
safety data sheet SDS. A fact sheet that details all the components of a substance and any associated health or safety hazards. A safety data sheet will list information such as cutting fluid composition, stability and reactivity, and physical and chemical properties.
safety goggles A type of tight-fitting eye protection that completely covers the eyes, the sockets, and the surrounding facial area. Safety goggles offer protection from any misting or splashing cutting fluid.
semi-chemical fluids A water-based cutting fluid containing a mixture of chemicals and soluble oil. Semi-chemical fluids, also called semi-synthetic fluids, are used in applications where lubrication and cooling are equally important, such as heavy-duty machining.
semi-chemical fluids A water-based cutting fluid containing a mixture of water, chemicals, and soluble oil. Semi-chemical fluids, also known as semi-synthetic fluids, are used when both lubrication and cooling are important.
semi-synthetic fluids A water-based cutting fluid containing a mixture of chemicals and soluble oil. Semi-synthetic fluids, also called semi-chemical fluids, are used in applications where lubrication and cooling are equally important, such as heavy-duty machining.
service life The length of time a cutting tool is expected to be operational before it must be replaced. Service life can be improved through the use of cutting fluids.
severe machining A machining operation occurring under very high pressures and temperatures. Severe machining operations can have improved part quality through the use of cutting fluids.
skimmer A device that uses a rotating wheel or belt to remove unwanted materials from the surface of a liquid. A skimmer can be used to remove debris or tramp oil floating on a cutting fluid.
soaps A substance made of natural oils or fats combined with a strong alkali material. Soaps are added to chemical cutting fluids to improve lubrication.
solid lubricants A lubricant with a thick, sticky consistency. Solid lubricants, also known as pastes, can be mixed in with other materials or spread on a surface of an object, such as the surface of a cutting tool.
soluble oils A cutting fluid that is a mixture of water, water miscible oil, and/or chemical agents. Soluble oils provide better cooling than straight cutting oils.
soluble oils A cutting fluid that is composed of oil, emulsifiers, water, and other additives. Soluble oils, also known as emulsifiable oils, are obtained as a concentrate, which is then mixed with water.
spray mist cutting fluid application A method of delivering coolant to a metal cutting operation where a small amount of cutting fluid is dispersed over the cutting area through a high-velocity stream of air. The spray mist cutting fluid application reduces the overall amount of coolant needed in a cutting operation.
stability The ability of a fluid to maintain its integrity over time. Straight oils have excellent stability, which makes them easily recyclable.
steel A metal consisting of iron and carbon, often alloyed with other elements. Steel is the most common manufacturing metal.
stressed Subject to forces that attempt to break or deform. Stressed products must be machined in ways that help them resist damaging forces.
sulfochlorinated fatty oil An active cutting oil containing sulfur and chlorine for improved film lubrication. Sulfochlorinated fatty oils provide especially good lubrication and help prevent pressure welds.
sulfochlorinated mineral oil An active cutting oil containing sulfur and chlorine for improved boundary lubrication. Sulfochlorinated mineral oils are particularly good for preventing pressure welds.
sulfur An abundant non-metallic chemical that can be added to some cutting fluids and is already present in others. Sulfur provides excellent lubrication when present in metal cutting fluids.
sulfurized mineral oil A mineral oil with added sulfur for improved boundary lubrication. Sulfurized mineral oil is often used in threading applications where the chips are crowded.
super-fatted fluids A semi-chemical cutting fluid with added animal or vegetable oil. Super-fatted fluids have improved lubrication properties.
super-fatted soluble oil A cutting fluid with added animal or vegetable fats for better boundary lubrication. Super-fatted soluble oils are often used for machining soft materials that create long, continuous chips.
surface finish The measured surface profile characteristics of a completed workpiece. The most important variable for surface finish is roughness, which can be reduced through the use of cutting fluids.
surface integrity The condition of the exterior of a workpiece after it has been machined. Excessive friction during metal cutting can reduce surface integrity and make a part unusable.
surface tension The tendency of a liquid to minimize its surface area by clinging to itself. Liquids with high surface tension will form into compact droplets when spreading over a surface.
surface-active agents A substance that reduces the surface tension of a liquid. Surface-active agents improve the wetting characteristics of a cutting fluid.
suspension A mixture in which small particles of one substance are dispersed evenly in another substance. Soluble oils are suspensions of oil in water.
synthetic fluid A cutting fluid made from water and chemicals, such as nitrites and phosphates. Synthetic fluids, also known as chemical fluids, are primarily used for their ability to cool.
tapping A metal cutting process that uses a rotating multi-point tool to produce internal threads in a workpiece. Tapping often requires the use of cutting fluids that provide excellent lubrication.
tensile strength The maximum stress, or tension, a material can endure before it breaks. Tensile strength affects how much heat a metal generates when it is being cut.
testing strips Thin strips of specialized paper used to check the pH of a liquid. Testing strips change color to indicate pH.
thermal cracking A fissure in a workpiece or tool caused by extreme fluctuations in temperature. Thermal cracking can occur when using cutting fluid delivery methods such as flood or HPHV.
thread cutting A method of producing screw threads that generally uses a single-point tool to cut a blank or workpiece as it rotates on a lathe. Thread cutting procedures are usually performed with sulfochlorinated mineral oils since they prevent pressure welds.
threading The process of cutting a long, spiraling groove into a cylindrical workpiece. Threading applications often require the use of active cutting oils to prevent chip crowding.
through-hole HPHV A method of fluid delivery in which fluid is delivered through channels or holes in the tool. Through-hole HPHV is used when the cutting surface would be unreachable by other methods.
titanium A silver-gray, strong but lightweight metal known for its corrosion resistance and high strength-to-weight ratio. Titanium produces a large amount of heat when being cut and requires cutting fluids with good cooling properties.
tool steels A specialized type of alloy steel that has excellent strength, toughness, and wear resistance. Because of their hardness, tool steels require special cutting fluid consideration when being machined.
tough A metal that can absorb energy without breaking or fracturing. Tough metals often require cutting fluids that provide excellent lubrication.
toxicology A branch of study concerned with the adverse effects chemicals can have on people. Toxicology reports help operators understand which chemical fluids must be handled with particular care.
tramp oil Hydraulic oil or grease from the machine tool that has contaminated the cutting fluid. Tramp oil can negatively affect the properties of a cutting fluid and must be removed from the fluid.
true solutions A type of cutting fluid in which all the components are evenly distributed. Chemical or synthetic cutting fluids are usually true solutions.
turning A machining operation that rotates a cylindrical workpiece while a single-point tool is guided along the length of the part. Turning operations often require cutting fluids with good cooling properties.
vacuum filter units A device that removes unwanted material through the use of suction and a separating device. Vacuum filter units are used to clean cutting fluids.
vegetable oil Any one of the various oils obtained from plants. Vegetable oils may be used in straight oil combinations to lubricate a metal cutting process.
ventilation A means of providing fresh air. Ventilation is essential to ensure operator safety when using spray mist or MQL fluid application.
viscosity The measure of how easily a fluid moves or flows. Low viscosity fluids flow easily, high viscosity fluids flow less easily.
water hardness A measure of the amount of minerals dissolved in water. Water hardness can affect the effectiveness of cutting fluids and must be carefully monitored.
water-miscible cutting fluids A coolant that is at least partially composed of water. Water-miscible cutting fluids include soluble oils, synthetic fluids, and semi-synthetic fluids and provide lubrication and cooling during the metal cutting process.
water-miscible cutting fluids A coolant that is capable of being mixed with water and is at least partially composed of water. Water-miscible cutting fluids include soluble oils, chemical fluids, and semi-chemical fluids and provide lubrication and cooling during the metal cutting process.
waxes A moldable, spreadable substance that can be used as a lubricant. Waxes do not provide any cooling during metal cutting processes.
wet To cover with liquid. Effective cutting fluids must thoroughly wet the workpiece and cutting tool.
workpiece A part that is subjected to one or more manufacturing procedures, such as welding, machining, or casting. During machining processes, a workpiece is often protected from defects through the use of a cutting fluid.
worksite The general area where manufacturing processes are performed. A worksite must be cleaned and properly maintained to ensure operator safety.