“I have to take apart a small heater. It has a screw on it I’ve never seen before. The screw head has a triangle cut in to it. What kind of screwdriver does it take?” The patron had brought the small black screw along with him to show the Newton Falls Public Library staff. Those working that day had never remembered seeing one like it before either.
Classic Hand Tools by Garrett Hack had wonderful information and photographs about a variety of woodworking tools, but no screwdrivers. Machine Shop Basics by Rex Miller and Mark Richard Miller was filled with details shop practices and tools, but no screws. It wasn’t until we got to Millwrights and Mechanics Guide by Carl A. Nelson that we were successful in finding information about screws. It was interesting to note that there are three basic forms of heads: flat, round, and oval which use either a straight-slotted or Phillips type driver. Nelson gave examples of nineteen different kinds many of which fall within these groups; some with intriguing names like filister, bung, felloe, pinched, and piano. In addition to the slotted and the Philips, the Reader’s Digest Complete Do-It-Yourself Manual gave examples of the square-drive [Robertson], star-drive [torx], one-way, and hex-head [Allen], but no triangular. This book did give troubleshooting tips for problems with electric heaters.
Searching the Internet for triangular screws and screwdrivers brought up interesting results. Online shoppers can purchase triangular screwdrivers for use on watches, robot vacuum cleaners, children’s fast food meal toys, and we assume from the reference question, small electric heaters; and tri-wing Y ones for electronic game consoles. These are security screws, designed to deter those seeking to disassemble the product. Other security screws found were snake eyes, reverse thread, one-way slotted, and pin heads. There are also drivers made for removing each kind.