Abstract: The present invention relates to a screw element (1) comprising a threaded shaft (2), a screw tip (4) formed on one shaft end and a screw head (5), formed on an opposite shaft end and with force application means (7), and comprising a screw thread (12) extending on the threaded shaft (2) and on the screw tip (4), wherein the screw tip (4) has a front tip section (4a) tapering toward the screw element end, when viewed in the screwing-in direction (Z), and a section (4b) formed on the threaded shaft with a polygonal cross section, when viewed in cross section, whose enveloping circle diameter (dh) is greater than a core diameter (dk) of the screw tip (4), and the polygonal cross section has a corner point (15) lying on the enveloping circle of the section (4b), and a front edge surface (9), radially oriented with respect to a longitudinal center axis (X-X), ends in said corner point in the sense of an increased diameter.

Abstract: The present invention relates to a screw, in particular a plug screw, having a screw shank (1), a screw head (2) and a tapering screw tip (4), and having a screw thread (6) that extends at least over a portion of the screw shank (1) and over the screw tip (4), the flight (6a) of said screw thread (6) having a triangular cross section as seen in longitudinal section, with two thread flanks (8, 9) that intersect at a flank tip (7). The flank tip (7) is rounded, wherein a radius of the rounding of the rounded flank tip (7) is selected to be from 1% to 10% of the nominal diameter of the screw. The thread flanks (8, 9) are each formed from two flank portions which enclose an obtuse angle with one another.

Abstract: The present invention relates to a screw, in particular a plug screw, having a screw shank (1), a screw head (2) and a tapering screw tip (4), and having a screw thread (6) that extends at least over a portion of the screw shank (1) and over the screw tip (4), the flight (6a) of said screw thread (6) having a triangular cross section as seen in longitudinal section, with two thread flanks (8, 9) that intersect at a flank tip (7). The flank tip (7) is rounded, wherein a radius of the rounding of the rounded flank tip (7) is selected to be from 1% to 10% of the nominal diameter of the screw. The thread flanks (8, 9) are each formed from two flank portions which enclose an obtuse angle with one another.

Abstract: A screw element (1), having a threaded shank (2) and a screw tip (4), on one shank end, and a screw head (5) on the opposite end with force-application means (7), and a screw thread (12) on the threaded shank (2) and the screw tip (4). The screw tip (4), has a front first tip portion (4a), which tapers towards the end of the screw element, and a second adjacent tip portion (4b), having, a polygonal cross section, with an enveloping circle diameter (dh) larger than a core diameter (dk) of the first tip portion (4a). On the transition between the first and the second tip portions 4a,4b) at least one end edge face is radially oriented in the diameter enlargement and terminates in a vertex (15) of the polygonal cross section, which lies on the enveloping circle of the second tip portion (4b).

Abstract: Disclosed is an auxiliary device (1) for alignment of floor boards (2) when laying plank flooring. The auxiliary device is a tensioning unit (10) with two floor-side, protruding, lower contact jaws (12, 14) for resting against board side edges. The contact jaws are joined together via a displacement guide (16) for changing of their mutual internal distance (X1, X2), and with an upper lever mechanism (18) positioned opposite the lower, floor-side contact jaws (12, 14). The lever mechanism (18) is designed according to the toggle principle and is connected to the contact jaws (12, 14) such that by pivoting of the lever mechanism (18) the contact jaws (12, 14) can be moved from a starting position with a larger distance (X1) into a tensioned position with a smaller, defined distance (X2).

Abstract: Disclosed is an auxiliary device (1) for alignment of floor boards (2) when laying plank flooring. The auxiliary device is a tensioning unit (10) with two floor-side, protruding, lower contact jaws (12, 14) for resting against board side edges. The contact jaws are joined together via a displacement guide (16) for changing of their mutual internal distance (X1, X2), and with an upper lever mechanism (18) positioned opposite the lower, floor-side contact jaws (12, 14). The lever mechanism (18) is designed according to the toggle principle and is connected to the contact jaws (12, 14) such that by pivoting of the lever mechanism (18) the contact jaws (12, 14) can be moved from a starting position with a larger distance (X1) into a tensioned position with a smaller, defined distance (X2).

Abstract: The invention relates to a self-boring and thread-forming tapping screw having a screw shaft with a screw tip at one end and at the other end a force application member for the transmission of a turning moment. The screw shaft includes a threaded section with the screw tip and an adjacent thread-free section of the shaft including the force application member. The threaded section has a shaft core and a self-tapping thread. The threaded section includes a core section axially displaced from the tip and having a polygonal core cross section. Corners of the core cross section define an enveloping circle with an enveloping circle diameter larger than a shaft diameter of the thread-free section.