Indexable parting and grooving inserts mount to a compatible toolholder or cut-off blade in a lathe or CNC turning machine to remove sections of material or add grooves to workpieces. The inserts may have one cutting edge or multiple cutting edges, and they can be exchanged for new ones of the same style or a different style that's compatible with the toolholder or cut-off blade without removing it from the machine. Inserts with multiple edges can be rotated (indexed) to expose a fresh cutting edge when the old one dulls. Indexable parting and grooving 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.