Diamond-shape turning inserts have four sides of equal length and two acute (less than 90°) cutting points at opposite corners. Also known as rhombic inserts, they are used for general turning operations. These indexable inserts mount to a compatible toolholder, which attaches to a lathe or CNC turning machine. They can be rotated (indexed) to expose a fresh cutting edge when the old one dulls. They can be exchanged for new ones of the same style or a different style that's compatible with the toolholder without removing it from the machine. Diamond turning inserts are differentiated by their nose angle measurements. Narrow cutting-point nose angles provide small cutting depths and decreased vibration while wide cutting-point nose angles provide large cutting depths and increased cutting force. Indexable turning tools require fewer tool changes than solid tools in high-volume metalworking and fabrication applications with high speeds, high feeds, and difficult-to-machine materials.