The history of human use of cutting fluids can be traced back to ancient times. When people polished stone, copper and iron tools, they knew that watering could improve efficiency and quality. In ancient Roman times, olive oil was used when turning castings for piston pumps, and in the 16th century, tallow and water solvents were used to polish metal armor. Since the British John Wilkinson (J. Wilkinson) successfully developed a boring machine in 1775 to process the cylinder of the Watt steam engine, the application of water and oil in metal cutting has appeared. After a long development by 1860, various machine tools such as turning, milling, planing, grinding, gear processing and thread processing appeared one after another, which also marked the beginning of large-scale application of cutting fluids.
In the 1880s, American scientists took the lead in evaluating cutting fluids. F·W·Taylor discovered and clarified the phenomenon and mechanism that using a pump to supply sodium carbonate aqueous solution can increase the cutting speed by 30 to 40%. Since the tool material used at that time was carbon tool steel, the main function of the cutting fluid was cooling, so the term "coolant" was proposed. Since then, people have called cutting fluids cooling lubricants.
With the continuous improvement of people's understanding of cutting fluids and the continuous enrichment of practical experience, it is found that injecting oil into the cutting area can obtain a good machined surface. At first, people used animal and vegetable oils as cutting fluids, but animal and vegetable oils are easy to deteriorate and have a short service life. At the beginning of the 20th century, people began to refine lubricating oil from crude oil and invented various lubricating additives with excellent performance. After World War I, compound oils synthesized from mineral oils and animal and vegetable oils began to be studied and used. In 1924, cutting oils containing sulfur and chlorine were patented and used for heavy cutting, broaching, threading and gear machining.
The development of tool materials has promoted the development of cutting fluids. High-speed steel was invented in 1898, and the cutting speed increased by 2 to 4 times. In 1927, Germany first developed cemented carbide, and its cutting speed was 2 to 5 times higher than that of high-speed steel. With the continuous increase of cutting temperature, the cooling performance of oil-based cutting fluid can no longer fully meet the cutting requirements. At this time, people began to pay attention to the advantages of water-based cutting fluid again. Oil-in-water emulsion was produced in 1915 and became the preferred cutting fluid for heavy cutting in 1920. The first oil-free synthetic cutting fluid was developed in the United States in 1945. The world's first fully synthetic metal cutting fluid was successfully developed by Cimcool Cincinnati Milling Machine Company (later renamed Cincinnati-Milacron) and marked with a unique pink color. This product, CIMCOOL is revolutionary. At its birth in 1945, the only cutting fluid options were pure oil and milk-like emulsions. Because CIMCOOL is a water-based product, its cooling performance is twice that of pure oil. Unlike oil, it has no smoke and no fire hazard, and the processed parts are clean. Similar to emulsions, CIMCOOL maintains excellent cooling properties, and with the help of a unique chemically synthesized lubricant, its lubricity is developed, allowing higher cutting speeds and improved tool life. CIMCOOL shows high resistance to bacterial attack and its transparent properties are acceptable to industry. CIMCOOL is a significant step forward in the field of metalworking fluid technology. Other companies have turned to the development of chemical metalworking fluids to promote the development of cutting fluid technology. With the in-depth development of advanced manufacturing technology and the strengthening of people's awareness of environmental protection, new requirements have been put forward for cutting fluid technology, which will surely promote the development of cutting fluid technology to higher fields.