A thought screw. (Machine-translation by Google Translate, not legally binding)

摘要

A drilling screw comprising an elongated rod, means for admitting the driving tool forming an integral part with a rear end of said rod, said rod including a forged end of a drilling end in a part of the forward end thereof, and steps of a screw propeller helical extending along said stem and having a predetermined maximum peak diameter and a smaller bottom diameter, said bore end portion comprising a body having a smaller diameter than the predetermined peak diameter and larger, that said bottom diameter, a pair of opposingly forged striations means arranged in quadrants of said body diagonally located from each other substantially on opposite sides of a first plenum containing the longitudinal axis of said stem, said body including penetrating end surfaces that extend outward and axially rearwardly between the said flute means, said flute means being partially defined by a first flute surface which intersect said end surfaces in the cutting edges continuous to said plane, passing through the said flute surfaces to a second plane in the closeness of a terminal end of said body, said second plane also containing said axis and arranged perpendicular to said first plane, said body including a narrow fin between said surfaces of grooves at the free end, presenting a narrow edge tip for initial engagement with a workpiece during a drilling operation, said cutting edges extending outwardly and rearwardly from said tip edge to the peripheral edges of the body expressed, and the said end surfaces being forged and debonded. Behind the expr these sharp edges. (Machine-translation by Google Translate, not legally binding)