The presence and efficiency of cutting fluid is listed as a factor affecting optimum cutting speed. True or false?

• A. True
• B. False
• C. Not applicable
• D. Not specified

Answer: (A)

The presence and efficiency of cutting fluid is a factor affecting optimum cutting speed. Cutting fluids cool the cutting zone, lubricate the tool–workpiece interface, and help flush away chips. These effects reduce tool wear and overheating, which can allow higher cutting speeds while maintaining acceptable tool life and surface finish. If coolant is absent or ineffective, temperatures rise quickly, increasing wear and the risk of poor surface quality, so the optimal speed would be lower to compensate. The type and delivery of coolant, as well as its concentration, influence how effectively heat is removed and lubrication is provided, shifting what constitutes the best cutting speed in a given situation.