A frame spar and/or sash spar for a frame and/or a sash of a window, a door, or a façade element, which respectively has at least the following features: - a main profile (300, 400) having a substantially U-shaped cross section in one-piece or multipiece design, which, viewed in cross section, has a short leg and a long leg and also a transverse leg formed between them, - wherein a free intermediate space, which is overlapped at least in sections by a cover element and/or a fitting part, is formed between the ends of the short leg and the long leg facing away from the transverse leg, - wherein both the short leg and also the long leg of the main profile (300, 400) each have multifunction contours (20, 21) on the inner side thereof facing toward one another, - wherein the multifunction contours entirely or partially delimit at least the following grooves: - in each case a fastening groove (20b, 21b) formed on the side facing away from the transverse leg and open in the same direction for fixing a corresponding fastening means of the fitting part and/or the cover element for engaging over the intermediate space between the longitudinal leg and the short leg; - in each case a receiving groove (20c, 21c), wherein these receiving grooves (20c, 21c) are designed as undercut grooves, and wherein these receiving grooves (20c, 21c) are open on sides facing one another, in a direction parallel to the transverse leg, characterized in that - the fastening grooves (20b, 21b) are delimited by parallel webs (40, 41) of the short leg and the long leg and are partially formed with which delimit hollow chambers (37, 38) and by angled webs (31, 32) formed thereon at the sides facing each other, so that the parallel webs (40, 41) and the angled webs (31, 32) respectively form the fastening grooves (20b, 21b) standing open; and in that the receiving grooves (20c, 21c) which are open on their sides facing each other - in a direction parallel to the transverse leg - are formed on the sides of the parallel webs (40, 41) facing each other. - a main profile (300, 400) having a substantially U-shaped cross section in one-piece or multipiece design, which, viewed in cross section, has a short leg and a long leg and also a transverse leg formed between them, - wherein a free intermediate space, which is overlapped at least in sections by a cover element and/or a fitting part, is formed between the ends of the short leg and the long leg facing away from the transverse leg, - wherein both the short leg and also the long leg of the main profile (300, 400) each have multifunction contours (20, 21) on the inner side thereof facing toward one another, - wherein the multifunction contours entirely or partially delimit at least the following grooves: - in each case a fastening groove (20b, 21b) formed on the side facing away from the transverse leg and open in the same direction for fixing a corresponding fastening means of the fitting part and/or the cover element for engaging over the intermediate space between the longitudinal leg and the short leg; - in each case a receiving groove (20c, 21c), wherein these receiving grooves (20c, 21c) are designed as undercut grooves, and wherein these receiving grooves (20c, 21c) are open on sides facing one another, in a direction parallel to the transverse leg, characterized in that - the fastening grooves (20b, 21b) are delimited by parallel webs (40, 41) of the short leg and the long leg and are partially formed with which delimit hollow chambers (37, 38) and by angled webs (31, 32) formed thereon at the sides facing each other, so that the parallel webs (40, 41) and the angled webs (31, 32) respectively form the fastening grooves (20b, 21b) standing open; and in that the receiving grooves (20c, 21c) which are open on their sides facing each other - in a direction parallel to the transverse leg - are formed on the sides of the parallel webs (40, 41) facing each other. - in each case a fastening groove (20b, 21b) formed on the side facing away from the transverse leg and open in the same direction for fixing a corresponding fastening means of the fitting part and/or the cover element for engaging over the intermediate space between the longitudinal leg and the short leg; - in each case a receiving groove (20c, 21c), wherein these receiving grooves (20c, 21c) are designed as undercut grooves, and wherein these receiving grooves (20c, 21c) are open on sides facing one another, in a direction parallel to the transverse leg, - the fastening grooves (20b, 21b) are delimited by parallel webs (40, 41) of the short leg and the long leg and are partially formed with which delimit hollow chambers (37, 38) and by angled webs (31, 32) formed thereon at the sides facing each other, so that the parallel webs (40, 41) and the angled webs (31, 32) respectively form the fastening grooves (20b, 21b) standing open; and in that the receiving grooves (20c, 21c) which are open on their sides facing each other - in a direction parallel to the transverse leg - are formed on the sides of the parallel webs (40, 41) facing each other.