“Trident” Tri Groove Security Nuts
Tri Groove security nuts are nuts that are installed with a very unconventional drive. These nuts have three slots in them, making them unique in shape and appearance. They have a cone shape, designed to be gripped only by the device intended to tighten and loosen them.
You can commonly find these in places where security or vandalism is a concern. To test these nuts we decided to install one ourselves and test a couple of different tools to see if we could remove them quickly.
First, we installed the nut using a tri-groove socket tool specially designed for this drive style. After install, we attempted to tamper with this fastener ourselves to determine what it would take to remove it.
We tried using an adjustable wrench. That didn’t work, the cone shape of the nut showed no gripping areas to lock the wrench into. We also tried pliers which had the same effect. Vice grips were our last attempt to break this nut loose with a conventional tool. However, the cone shape made it incredibly difficult to find a locking point. So we attempted to grab the lip and the base of the installation. The lip proved to be too small to get a good grip, leading us to our conclusion.
Having tested several different removal methods for removing this nut, we have determined that without either the proper tool or physically altering the shape of the nut (perhaps with a grinder) to provide a gripping point for more conventional tools, it is unlikely that this nut will be easily tampered with when installed correctly.
*Although these nuts are fairly secure there is still a chance that someone could have enough know-how or time to alter the shape of the nut or may have come across the proper tool to remove them.