Patent ID: 8348574

Claim:
A self-drilling screw comprising: a screw head; a body formed on a bottom end of the screw head and having a screw rod protruding longitudinally from the bottom end of the screw head; and a thread portion formed on an outer surface of the screw rod; a chip removal section formed on a bottom end of the body and having a chip removal rod protruding longitudinally from the bottom end of the screw rod and being thinner than the screw rod; a chip removal thread portion formed on an outer surface of the chip removal rod wherein the outer diameter of the chip removal thread portion is close to the diameter of the screw rod; and a spiral chip removal groove formed in the chip removal thread portion; and a drilling blade being flat with a tapered end and formed on a bottom end of the chip removal section wherein the width of the drilling blade is smaller than the outer diameter of the thread portion and is slightly bigger than the diameter of the screw rod, wherein the body has a cone section formed adjacent to the chip removal section wherein the diameter of the cone section is gradually smaller towards the chip removal section; and the cone section has multiple lengthwise furrows formed on the outer surface of the cone section and multiple cone thread portions formed on the outer surface of the cone section wherein each cone thread portion is formed between two furrows.