Cutting fluid is a compound available for use in machining metal to lubricate and cool the metal while a worker cuts and shapes it. With a few exceptions, people like to work metal “wet,” with cutting fluid, because it is safer and easier than working with metal in a dry state. Numerous companies manufacture a range of machining products of this type, ranging from pastes to aerosol sprays. Machining facilities usually keep several types in stock to make sure people will have access to the materials they need.
When people cut metal, the friction generates a great deal of heat. This heat can deform both the metal and the cutting tools, making a coolant critical. Cutting fluid helps cool the metal, as well as lubricating to reduce friction, limiting the amount of heating during the cutting process. This allows people to make cuts with narrower tolerances, producing precisely machined parts, and also keeps the work environment safer. If metal gets too hot, it can crack or explode from stress, damaging equipment and putting workers at risk.
The cutting fluid helps to maintain a stable temperature, limiting risks of thermal shock, where metals get hot or cold very quickly. Even if the temperatures are within a safe range for the metal, the rapidity of the temperature changes creates stress. Fluids also keep down dust, metal particles, and shavings, contributing to worker safety by limiting the chances of inhaling particles of metal, in combination with facial protection like respirators. Specific compounds may confer additional benefits, depending on the product.
Cutting fluids can be painted, poured, sprayed, or applied in other ways. Thick compounds like pastes and gels may require hand application, to make sure they spread evenly. Thinner fluids may work in a sprayer. Often, machining equipment has a built-in sprayer for lubrication and cooling, so people do not need to apply the cutting fluid with a separate device.
One risk with cutting fluid is the hazard posed by the fluid itself. Some are toxic and can make a workplace unsafe unless people handle them appropriately and dispose of them after use. Metalworkers may recycle cutting fluid, but eventually, it can clog with metal particles, making it useless. Facilities need to install proper equipment for collecting the fluid so they can recycle or dispose of it, and some companies use products like biodegradable cutting fluids to cut down on environmental hazards.