Patent ID: 7090452
Filing Date: 2006-08-15
Classification: F16B

Abstract:
1. A tapping screw comprising: a head, a shank extending down from said head and having male threads, and a cylindrical cutting member extending down from said shank, said cutting member provided with a plurality of lengthwise cutting grooves and a plurality of lengthwise wings projecting out from said cutting member, an annular groove provided between said shank and said cutting member, said annular groove serving for a large volume of wood waste cut to move in from a drilled hole in an object being screwed in by said screw so that cutting capacity of said screw may be kept as usual and torque required for fixing said screw may be reduced; wherein said wings of said cutting member are formed as generally flat members on an outer surface of the cutting member, a diameter of said cylindrical cutting member is larger than a diameter of said annular groove, wherein one end of each of the cutting grooves starts from a tip of the cutting member and the other end of each of the cutting grooves extends into the annular groove, and each of the cutting grooves includes a smooth continuous surface extending from the tip to the annular groove.