Self-drilling Screws

Self Drilling Screws were created in response to higher volume sheet metal applications. The threads are variations on either tapping (spaced) threads or machine screw threads); however, a drill point has been added to the tip of the screw. The purpose is to drill a hole through thin metal without the need of a pilot hole. It taps or forms mating threads without deforming its own thread or breaking during the assembly process. In order to accomplish these essentials, a special heat treat specification was developed which is now known as SAEJ78.
There are two methods for making the drill point on this type of screw. One is by milling (or cutting) and provides a very precise cutting angle on the screw. The drawback is that this a slower, more costly process. The alternative is a forged point (also known as a pinched point) which is faster to produce; however, it is limited in certain applications because it is less precise than the alternative method. The length of the point is determined by the material that must be penetrated by the drill tip.
The most popular brand is known as the TEK screw and was developed by ITW. The original patent has expired and the term “self drilling screw” and TEK have become interchangeable.
DRIVE STYLES: Robertson
HEAD STYLES: External Torx