Barrel nut screwdrivers are special tools that simplify the installation and removal of “barrel nuts” that are commonly used on most Navy terminal boards and fuse panels. The barrel nut is round, with a slotted top to accommodate a screwdriver. The stud on which the barrel nut is installed is frequently long enough to protrude through the barrel nut making it difficult, if not impossible, to engage, or maintain engagement with the slot in the barrel nut. The barrel nut screwdriver has a spring-loaded pin that protrudes in the center of the slot. When extended, it provides a means of slipping the barrel nut onto the tool to simplify installation. As the nut threads onto the stud, the pin retracts, allowing the nut to be fully tightened. When removing the nut, the pin retracts as it contacts the stud, allowing full engagement with the slot in the nut so it can be removed. The screwdrivers are available for #6 and #8 threaded parts in overall lengths of 4-1/2″, 8-1/2″ or 12-3/4″ and for #4 threads in the length of 4-1/4″. Please order by description and part number as shown in the photo and as detailed in the individual listings.