Tool for cutting processing having a base member which has a rotation axis about which the tool rotates during operation, at least one seat which is formed on the base member for receiving a replaceable cutting insert, a securing screw for securing the cutting insert to the seat, and a cutting insert which is secured to the seat, wherein the seat has a base face for supporting a lower side of the cutting insert, and a first lateral abutment face for abutting against a first lateral face of the cutting insert, which first lateral abutment face supports the cutting insert in a radially inward direction, and a hole for receiving the securing screw is formed in the base face, wherein the hole has with spacing from the base face a threaded hole and closer in the direction of the base face a thread-free hole portion, wherein the securing screw has a threaded portion for cooperating with the threaded hole, a head portion for supporting in a through-hole of the cutting insert and between the threaded portion and the head portion a thread-free shaft portion, which thread-free shaft portion has a smaller cross section than the thread-free hole portion, wherein the cutting insert is secured to the seat in such a manner that the head portion of the securing screw is supported on the through-hole of the cutting insert, the threaded portion of the securing screw cooperates with the threaded hole and the head portion of the securing screw is resiliently deflected characterized in that the seat has a second lateral abutment face for abutting against a second lateral face of the cutting insert, which second lateral abutment face supports the cutting insert axially and in a radially outward direction and that the head portion of the securing screw is resiliently deflected in such a manner that the thread-free shaft portion is supported when viewed in a direction perpendicular to the base face in a second quadrant which is located in a radially outward direction and axially in the direction of a free end of the tool on the thread-free hole portion. a base member which has a rotation axis about which the tool rotates during operation, at least one seat which is formed on the base member for receiving a replaceable cutting insert, a securing screw for securing the cutting insert to the seat, and a cutting insert which is secured to the seat, wherein the seat has a base face for supporting a lower side of the cutting insert, and a first lateral abutment face for abutting against a first lateral face of the cutting insert, which first lateral abutment face supports the cutting insert in a radially inward direction, and a hole for receiving the securing screw is formed in the base face, wherein the hole has with spacing from the base face a threaded hole and closer in the direction of the base face a thread-free hole portion, wherein the securing screw has a threaded portion for cooperating with the threaded hole, a head portion for supporting in a through-hole of the cutting insert and between the threaded portion and the head portion a thread-free shaft portion, which thread-free shaft portion has a smaller cross section than the thread-free hole portion, wherein the cutting insert is secured to the seat in such a manner that the head portion of the securing screw is supported on the through-hole of the cutting insert, the threaded portion of the securing screw cooperates with the threaded hole and the head portion of the securing screw is resiliently deflected characterized in that the seat has a second lateral abutment face for abutting against a second lateral face of the cutting insert, which second lateral abutment face supports the cutting insert axially and in a radially outward direction and that the head portion of the securing screw is resiliently deflected in such a manner that the thread-free shaft portion is supported when viewed in a direction perpendicular to the base face in a second quadrant which is located in a radially outward direction and axially in the direction of a free end of the tool on the thread-free hole portion.