What type of materials typically have low machinability ratings?

Superalloys are materials that typically have low machinability ratings due to their unique composition and properties. These alloys are designed to withstand extreme temperatures, pressures, and corrosive environments, making them ideal for aerospace and energy applications. However, the very characteristics that make superalloys so durable also make them challenging to machine.

Their high strength and toughness result in greater tool wear, increased cutting forces, and more difficulty in achieving precise dimensions compared to softer or more ductile materials. Consequently, specialized machining techniques, tools, and conditions are often required to work with superalloys efficiently, further contributing to their low machinability ratings.

In contrast, soft metals are easier to machine; plastics generally have favorable machinability characteristics due to their low density and easy cutting. Wood composites are also typically easier to work with in comparison to very high-performance materials like superalloys.