US Patent 10092341 Screw

A screw has a screw tip defined at a forward end of the screw. A screw head is formed at a rear end of the screw. A screw thread helically extends from adjacent the screw tip towards the screw head. The screw thread has a series of successive screw thread portions each helically extending through 360 degrees. At least one flute extends from adjacent the screw tip towards the screw head through at least one of the screw thread portions. For each flute, a leading edge region of each of at least one screw thread portion through which the flute extends is convexly curved. Each leading edge region is defined by a trailing wall of the flute adjacent a crest of the respective screw thread portion.