TH115577B - Self-drilling screw - Google Patents

Abstract

Self-drilling screw for fixing roofing material or other cladding to wood or A non-metal with a saw tooth spreading along the helix is at an angle to the axis of the shaft rather than the wing. The helix has a sharp edge not more than 0.25 mm wide which allows the thread to penetrate. In all wood logs, from soft to very hard, the shape of the spread also makes the spiral. It can be moved into a thick steel board while still maintaining its strength. It pulls very well when it moves into a thin metal board because it results in Work of Sawtooth Spiral

Claims (1)

1. Screw for fixing roofing material or other cladding material. With wooden or metal support parts The screw has a perforation at the front end and part of the shaft. Made a thread behind the drilled part. The drill has opposite cross-section edges at the ends. Outside and groove that extends axially backwards from the cross-sectional edge The threaded rod is made to a threaded tee (as defined here), which is started at the end of the drill bit away from the cutting edge and More and more. Over a number of bends to the highest point of the thread The drill has lines. Through the center of constant