Indexable parting and cut-off blades have a slim profile and use cutting inserts to make deep cuts or remove sections of material as the blades are fed into the side of rotating bar stock or workpieces. They mount to a cut-off tool block or holder in a lathe or turning machine and have a notched corner that holds an indexable insert. 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 tool block or holder without removing it from the machine. Inserts with multiple cutting edges can be rotated (indexed) to expose a fresh cutting edge when the old one dulls. Indexable parting 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.