Which statement is true about carbide cutting tools compared with high-speed steel?

Which statement is true about carbide cutting tools compared with high-speed steel?

• A. Carbide can be resharpened but wears faster.
• B. Carbide is harder and holds an edge longer but is more brittle; HSS is tougher and resharpenable but wears faster.
• C. Carbide is cheaper and easier to sharpen than HSS.
• D. HSS is harder than carbide.

Answer: (B)

Understanding how hardness, edge retention, and toughness differ between carbide and high-speed steel helps explain why one material can keep a sharp edge longer while the other handles cutting shocks better. Carbide cutting tools are extremely hard, so they hold a sharp edge for a long time and resist wear well in many cutting conditions, especially at high speeds and when cutting hard materials. But this hardness brings brittleness: the rigid carbide structure can chip or fracture under heavy cutting forces or sudden impacts. High-speed steel, on the other hand, is tougher and more ductile, so it absorbs shocks more effectively and can be ground to restore a sharp edge multiple times, but it isn’t as hard as carbide, so it wears away faster under the same conditions. Therefore, describing carbide as harder and edge-holding yet more brittle, while high-speed steel is tougher and resharpenable but wears faster, accurately reflects the real trade-off between these tool materials.

Understanding how hardness, edge retention, and toughness differ between carbide and high-speed steel helps explain why one material can keep a sharp edge longer while the other handles cutting shocks better. Carbide cutting tools are extremely hard, so they hold a sharp edge for a long time and resist wear well in many cutting conditions, especially at high speeds and when cutting hard materials. But this hardness brings brittleness: the rigid carbide structure can chip or fracture under heavy cutting forces or sudden impacts. High-speed steel, on the other hand, is tougher and more ductile, so it absorbs shocks more effectively and can be ground to restore a sharp edge multiple times, but it isn’t as hard as carbide, so it wears away faster under the same conditions. Therefore, describing carbide as harder and edge-holding yet more brittle, while high-speed steel is tougher and resharpenable but wears faster, accurately reflects the real trade-off between these tool materials.