The invention relates to a rotary tool (1; 101; 201; 301; 401) for cutting large inside diameters at the outer circumference (2) of which at least one cutting edge (4; 104; 204) is arranged, comprising a support structure (10; 110; 210; 310; 410) which includes a supporting area (14; 114; 214) which indirectly or directly supports the cutting edge (4; 104; 204), and comprising a chucking portion (24; 124; 224; 324; 424) for coupling to a tool holder, wherein the support structure (10; 110; 210; 310; 410) is designed in light-weight construction and the area (14; 114; 214) of the support structure (10; 110; 210; 310; 410) indirectly or directly supporting the cutting edge (4; 104; 204) is limited regarding thermal expansion by a corset structure (12; 112; 212; 312; 412).