Patent ID: 6979160

Claim:
Fastener element ( 700 ) having a fastener section ( 702 ) and a tubular piercing or rivet section ( 704 ) having a radially inner side, a radially outer side, a central longitudinal axis, and a radial wall thickness (R) with the piercing or rivet section being designed for the attachment of the fastener element to a sheet metal part and with the fastener section being designed for the attachment of an article to the sheet metal part, wherein, in a region of transition from the fastener section ( 702 ) into the piercing or rivet section, a radially or conically extending contact surface ( 708 ) is provided and the tubular piercing or rivet section has at its free end face ( 714 ) on the radially inner side a conical inclined surface or cutting surface ( 716 ) which diverges in the direction of the free end face and at the radially outer side a rounded pressing and drawing surface ( 718 ), with the inclined surface or cutting surface ( 716 ) and the pressing and drawing surface ( 718 ) meeting at an annular end face edge ( 720 ) at the free end face of the piercing or rivet section ( 704 ), characterized in that the conical inclined surface or cutting surface ( 716 ) forms an hypotenuse of an imaginary right angled triangle with a limb length perpendicular to the central longitudinal axis ( 726 ) of the tubular piercing or rivet section ( 204 ) of 0.10 mm±0.03 mm, in that the radial wall thickness (R) of the tubular piercing or rivet section ( 704 ) is dimensioned as a function of an effective size of the fastener section; that the rounded pressing and drawing surface ( 718 ) has a radius of curvature (r) which is 0.1 mm±0.03 smaller than the respective radial wall thickness (R) and in that the centre of curvature ( 727 ) of the rounded pressing and drawing surface ( 718 ) lies on the surface of an imaginary cylinider ( 728 ) parallel to the central longitudinal axis which an imaginary cylinder's ( 728 ) surface, said cylinder parallel to an axis which extends away from the annular end face edge ( 720 ) in the direction of the fastener section ( 702 ) and is so positioned at a point along the piercing or riveting section ( 704 ) on the surface of the imaginary axially parallel cylinder ( 728 ) that a tangent ( 730 ) to the rounded pressing and drawing surface ( 718 ) stands perpendicular to the central longitudinal axis ( 726 ) at the annular end face edge ( 720 ).