Working tool and machine for sawing and cutting

Working tool for sawing or cutting, comprising an annular blade (2) intended to be rotated about an axis of rotation, encircling said axis of rotation, the annular blade comprising an annular blank (3;

• 3′) and means (15), comprising a plurality of diamond segments (15), forming a working part of the tool and provided in connection to an outer edge (31) of the blank (3;
• 3′), said blank also having an inner edge (19), an inner edge portion (18) comprising driving surfaces for rotation of the tool about said axis of rotation, and a web portion (23) between said outer edge (31) of the blank and said inner edge portion (18) of the blank, said web portion having a first side (24) and a second side (27), wherein at least two substantially circular guide grooves (21,22;
• 21′, 22′) are provided in the web portion on its first side, said guide grooves including an inner groove (21;
• 21′), which is the guide groove that is nearest the inner edge, and an outer groove (22;
• 22′) which is the guide groove that is nearest the outer edge, the guide grooves being concentric with respect to said axis of rotation, and each guide groove having an inner wall (34, 35;
• 34′, 35′) on its inner side which faces the inner edge (19) of the blade, and the depth of the guide grooves (21′, 22′) are increasingly deeper in the direction from the inner groove towards the outer groove.