Reprint from Hardware & Fastener Components Magazine, Vol. 42

Precariously balancing atop a ladder, you find yourself holding the new light fixture you’re installing in one hand and in the other a screw driver with a screw delicately balanced from the tip. To your chagrin the ladder jiggles a little and the screw drops to the floor leaving you perched on a ladder holding a light fixture you can’t now connect. Whether you are into “do-it-yourself” projects or would never find yourself in this situation, this scenario repeats itself many times a day in many different ways throughout the world. Perhaps ending more successfully than the above example, the screw is driven into place providing the holding power it was designed to give. This is only possible because screws are designed with a drive feature, often an internal recess that accepts a screw driver bit that enables assembly.

Threaded fasteners, since their inception, have had to have some sort of design or feature that allowed them to be driven. Although most internal recesses are relatively new (less than 100 years old), slots have been used for a very long time. Slots are simple, easy to use, and pretty effective. However, newer designs introduce an array of technologies that address many of the challenges that fastener engineers and designers commonly face.