Keep your ball screw spinning without the ball nut damaging your system—a clutch-like collar inside the ball nut prevents it from travelling past the stop pins. Install the included stop pins anywhere along the length of the ball screw by drilling a hole in the valley of the threads (also known as the root) and pressing in the stop pin. When the collar meets the stop pin, the ball nut disengages from the threads and begins to idle. To start the ball nut travelling again, spin the ball screw in the opposite direction. All components are black-oxide steel and have mild corrosion resistance. To ensure compatibility, select components that have the same thread size. Ball nuts are furnished with a tube to keep ball bearings in place. Do not remove the tube until you are ready to install the nuts onto the screws.