Indexable boring tools are used with lathes or CNC turning machines to remove material from inside holes. They perform like standard boring tools but have a tool body or toolholder that accepts replaceable indexable inserts or modular heads to form a cutting edge. The inserts and heads can be swapped out for new ones of the same or different style without removing the tool body or toolholder from the machine. Indexable and modular reamers enlarge drilled holes. Indexable boring bars size, straighten, and finish the inside of drilled or cast holes. Indexable boring bar sets include multiple boring bars with different shank sizes, cutting head orientations, or insert shape and style compatibility. Indexable cutting unit heads for internal turning are used as part of modular, quick-change tool system. Indexable boring 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.