Self-drilling screw and use thereof
A self-drilling screw made of an austenitic or other stainless steel, is provided having a drilling tip. The shank is integrally formed of an austenitic or other stainless steel and has a galvanically applied thin coating at least in the tip region, with the coating being harder than a non-coated region. The thin coating has a pearl-like or columnar surface, a coating thickness of at least 2 μm and a hardness in a range of from 500 to 1500 HV0.3. The self-drilling screw can be produced more simply than a typical self-drilling screw, in which the drilling tip consists of a harder material than the shank and is welded to the shank made of stainless steel. The coating ensures the drilling capacity and thread formation.
1. A self-drilling screw comprising a shank having a thread-forming region and a drilling or penetrating tip, the shank and the drilling or penetrating tip formed ( 12 ) integrally of an austenitic or other stainless steel, a galvanically applied thin coating ( 20 ) at least in a region of the tip, the region provided with the coating ( 20 ) is harder than a non-coated region, the thin coating ( 20 ) including:
a beaded or columnar surface,
a coating thickness of at least 2 μm, and
a hardness in a range of from 500 to 1500 HV0.3.
2. The self-drilling screw according to claim 1 , wherein the galvanically applied thin coating ( 20 ) is a hard chromium coating.
3. The self-drilling screw according to claim 1 , wherein the galvanically applied thin coating ( 20 ) has an inherent roughness of 0.5 μm.
4. The self-drilling screw according to claim 1 , wherein the galvanically applied thin coating ( 20 ) is adapted to withstand a surface pressure of up to 3.0 GPa.
5. The self-drilling screw according to claim 1 , wherein the galvanically applied thin coating ( 20 ) is adapted to withstand a dynamic load of up to 3.5 MPa.
6. The self-drilling screw of claim 1 , wherein the coating thickness is up to 30 μm.
7. A method of connecting at least two components using the self-drilling screw ( 10 , 30 ) according to claim 1 , comprising rotating the self-drilling screw so that the drilling or penetrating tip cuts through the components, and continuing to rotate the self-drilling screw such that the thread forming region engages the at least two components for connecting the at least two components ( 40 , 42 , 50 , 52 , 54 , 56 ) to one another, one of which is exposed to the weather.
8. The method according to claim 7 , wherein the components ( 40 , 42 , 50 , 52 , 54 , 56 ) to be fastened to one another are components of a building cladding.