Self-tapping screw

A self-tapping screw comprising:

• a shank on which a thread of constant pitch is formed, the shank and thread being made of synthetic material, which shank defines a screw center line,
• wherein the shank has a proximal end and a distal end, the distal end of the shank being a distal insertion end of the screw,
• wherein the shank comprises a first portion (6a) located on the distal end of the shank and a second portion (6b) located on the proximal side of the first portion, the second portion extending towards and connecting with the first portion of the shank,
• wherein the thread is located on both the first and second portions and has the same pitch in the first and second portions,
• wherein the thread in the second portion is continuous and has a complete thread cross-section,
• wherein the thread in the first portion is non-continuous and, in a direction of the thread towards the distal end of the shank, the thread is divided into thread segments having an incomplete thread cross-section,
• wherein the thread segments have a leading end and a trailing end, the leading end being closer to the distal end of the shank than the trailing end, the thread segments further having a distal flank, a proximal flank, and a thread top that extends between the distal flank and the proximal flank and also between the leading end to the trailing end of each thread segment,
• wherein the thread top has a radial distance from the screw center line,
• wherein relative to the screw center line, the leading end of a first thread segment extends further in radial direction than the leading end of a second thread segment, the first thread segment being located towards the proximal end of the shank with respect to the second thread segment, such that a maximum radial length of the leading end of each of the thread segments, relative to the screw center line, decreases toward the distal end of the shank, each leading end forming a cutting edge,
• wherein, for a majority of thread segments, a radial distance from the screw center line to the thread top at any location along each respective one thread segment is equal to or less than the radial distance from the screw center line to the thread top at the leading end of that respective one thread segment, so that for each respective one thread segment of said majority of the thread segments, a thread contour taken along the respective one thread segment is situated on or within the thread contour of its respective leading end.