Handy information for Self tapping and Self Drilling Screws

Using the right screw for the job is essential, so here is some handy information about Self Drilling & Self Tapping Screws.

Also known as TEK screws, self drilling screws are a type of self tapping screw that feature a drill point.  The primary purpose of the drill point is to drill a pilot hole in the material that is being screwed into.  Self tapping threads are behind the drill point, forming the mating threads in the material.  

Self tapping screws cut their own thread but do not have a drilling point, which means that they are best for securing thinner sheet metals and other substrates.  If drilling into thicker materials a pilot hole must be pre-drilled as a separate function.  

Determining the Drilling Capacity of Self Drilling Screws

It is important to consider the drill flute, point length and whether you are fastening thicker material to metal when determining drilling capacity as all of these factors will impact on drilling capacity.

Drill flute -  The height of the flute will determine the thickness that the screw can penetrate.   If flutes become fully embedded in the material they will trap debris, causing it to heat and break.

Point Length - The unthreaded portion of the point, known as the pilot section must be long enough to completely penetrate the material before the threads engage.  Since the threads advance faster than the drilling process, if they engage before drilling is done the fastener can bind and break.

There are a number of issues that users might encounter if they are using self drilling screws incorrectly.  The table below lists a series of simple troubleshooting solutions that the operator can use to solve a number of common issues.