US Patent 10480561 Screw chip removal structure

Disclosed is a chip removal structure of a screw. The screw includes a screw head. A shank extends downward from the screw head. The shank has an outer circumferential surface on which a thread is formed in a surrounding form. The shank has a lower end that is formed with a tapering tail section. The thread is extended to the tapering tail section. The tapering tail section is formed, through cutting or pressing, with two or more chip removal grooves. The spacing distance of the chip removal grooves can be adjusted as desired. The chip removal grooves are set at an inclination angle and any one of the chip removal grooves may exceed or may not exceed a screw center line. The chip removal grooves on the left side are each 0.5 to 4.5 times in width of the chip removal grooves on the right side.