Abstract: A power compass saw with a housing that accommodates a lifting rod for the up and down movement of a longitudinal saw blade attached thereto, has a toothed side and a saw blade back and with a guide roller which supports the saw blade back and has a central groove into which the saw blade extends with its saw blade back and is guided therein, the central circumferential groove has tapered groove sides with a 5° taper, the saw blade back has a straight portion and an end beveled portion with beveled edges having a 7° taper at both sides, the saw blade back has diametrically opposed edges provided at a transition from the straight portion to the beveled portion, and the saw blade back has a width which is measured between the diametrically opposed edges and is greater than a width of a bottom of the circumferential groove.