A rotary boring tool with detachable inserts, including a rotating insert carrier body including cartridges holding detachable cutting inserts configured to machine a cylinder barrel by axial movement of the tool in the barrel, and including a first cutting insert configured to rough-cut grooves in the material to be machined, a second insert configured to finish the grooves roughly cut by the first insert, and a third levelling insert configured to level rough material generated by the first two inserts.