A tool unit for a cut and break cutting or sawing machine with a tool carrier, the tool unit being arranged to cut to a depth exceeding a radius of a disk shaped cutting blade, the tool unit comprising: a first tool comprising a disk shaped cutting blade and a first blade driving member; and a second part (2, 50), which second part (2, 50) comprises either a second blade driving member, or a second tool comprising a disk shaped cutting blade and a second blade driving member; wherein the first tool is secured to the second part (2, 50) by means of a central clamping unit (73,74, 75), wherein each cutting blade, has a central aperture defined by a central edge (14; 114), and a peripheral cutting edge, being the working part of the tool (1, 2); wherein the blade driving members (40, 50) are arranged to rotate together with the disk shaped cutting blade/s about an axis of rotation; wherein at least one of the driving members (40, 50) has a circumferential driving surface (41, 51) provided to be able to cooperate with an endless power transmission means, and wherein each blade driving member has a central attachment portion (44, 54) comprising at least one aperture (47, 57) for attaching the first driving member to the second driving member by using the central clamping unit (73, 74, 75); characterized in that a drive member (40, 50) comprises a main part (48, 58) and a blade supporting part, wherein the at least one disk shaped cutting blade has an at least partly recessed portion, adjacent to the central aperture, the recessed portion being arranged to be secured between the blade supporting part and the main part (48, 58), thereby attaching the disk shaped cutting blade to the corresponding blade driving member (40, 50) by holding the recessed portion axially between the main part (48, 58) and the blade supporting part of the corresponding blade driving member, ensuring an essentially flat outer extension plane of each tool (1,2). a first tool comprising a disk shaped cutting blade and a first blade driving member; and a second part (2, 50), which second part (2, 50) comprises either a second blade driving member, or a second tool comprising a disk shaped cutting blade and a second blade driving member; wherein the first tool is secured to the second part (2, 50) by means of a central clamping unit (73,74, 75), wherein each cutting blade, has a central aperture defined by a central edge (14; 114), and a peripheral cutting edge, being the working part of the tool (1, 2); wherein the blade driving members (40, 50) are arranged to rotate together with the disk shaped cutting blade/s about an axis of rotation; wherein at least one of the driving members (40, 50) has a circumferential driving surface (41, 51) provided to be able to cooperate with an endless power transmission means, and wherein each blade driving member has a central attachment portion (44, 54) comprising at least one aperture (47, 57) for attaching the first driving member to the second driving member by using the central clamping unit (73, 74, 75); a drive member (40, 50) comprises a main part (48, 58) and a blade supporting part, wherein the at least one disk shaped cutting blade has an at least partly recessed portion, adjacent to the central aperture, the recessed portion being arranged to be secured between the blade supporting part and the main part (48, 58), thereby attaching the disk shaped cutting blade to the corresponding blade driving member (40, 50) by holding the recessed portion axially between the main part (48, 58) and the blade supporting part of the corresponding blade driving member, ensuring an essentially flat outer extension plane of each tool (1,2).