Patent ID: 7850409

Claim:
A self-tapping fastening element, comprising a shaft ( 12 ); rotation-transmitting means ( 13 ) provided at one end ( 14 ) of the shaft ( 12 ), the shaft having a free end ( 16 ) remote from the rotation-transmitting means ( 13 ); and a tapping thread ( 21 ) carried by the shaft ( 12 ) and having at least one screw thread ( 22 , 42 ) with a thread pilot ( 35 ) located in a region ( 15 ) of the shaft free end ( 16 ), a section ( 23 ; 43 ) of the at least one screw thread ( 22 ; 42 ) that adjoins the thread pilot ( 35 ), having a plurality of thread steps following one another, in a circumferential direction, the thread steps ( 24 , 25 , 26 , 27 ; 44 , 45 , 46 , 47 ) each defined by a substantially radial face and a substantially circumferential face and having different size cross-sections, with a cross-section size of the at screw steps( 22 ; 42 ) continuously decreasing stepwise toward the thread pilot ( 35 ) from one thread step ( 24 , 25 , 26 , 27 ; 44 , 45 , 46 , 47 ) to a next thread step ( 24 , 25 , 26 , 27 ; 44 , 45 , 46 , 47 ), the thread steps ( 24 , 25 , 26 , 27 ; 44 , 45 , 46 , 47 ) having respective cutting edge-forming end surfaces ( 28 , 29 , 30 , 31 ; 48 , 49 , 50 , 51 ) aligned, at least partially, in a direction of the thread pilot ( 35 ).