These Long-Lok® Ball-Style Spring Plungers with Slotted Sockets have bodies, balls & springs made from Steel and feature the Long-Lok® Thread System for securing the plunger in any position within the threaded hole. Long-Lok®: Clockwise insertion into a tapped hole expands the Long-Lok® System in the opposite direction, increasing the resistance and therefore the amount of torque required for loosening.