Why is high-speed steel (HSS) favored for cutting tools?

High-speed steel (HSS) is favored for cutting tools primarily due to its ability to retain hardness at elevated temperatures. When cutting metals or other materials, friction generates significant heat, which can affect the cutting edge of the tool. HSS maintains its hardness under these conditions, allowing for consistent cutting performance without deforming or losing effectiveness.

The ability to perform well at high temperatures makes HSS suitable for applications that involve high cutting speeds, thus the name 'high-speed steel.' This characteristic contributes to longer tool life and reduces the need for frequent tool changes, improving overall machining efficiency.

While the other options may seem appealing, they do not accurately reflect the primary advantage of HSS. For instance, flexibility is not a dominant factor in the performance of cutting tools; rather, tool strength and durability are paramount. Although HSS can be sharpened fairly easily, this is secondary to its thermal stability in high-speed applications. The weight of a tool compared to carbide is often not a critical consideration in cutting-tool performance as much as its ability to withstand thermal conditions and maintain its cutting edge.