Highest cutting speed is achieved by the __________ tool material.

ANS:B - carbide

The highest cutting speed is typically achieved by carbide tool material. Carbide tool materials, such as cemented carbides (also known as hard metal or tungsten carbide), are widely used in cutting applications due to their exceptional hardness, wear resistance, and high temperature resistance. These properties allow carbide tools to withstand high cutting speeds and maintain sharp cutting edges for longer durations compared to other tool materials. In contrast, while high-speed steel (HSS) also offers good cutting performance, it generally cannot match the cutting speeds achievable with carbide tools. Cast alloys and plain carbon steel are not commonly used for cutting applications where high cutting speeds are required due to their inferior hardness and wear resistance compared to carbide and HSS.