Abstract: A hydraulic cylinder, piston and rod assembly wherein the piston is secured to the rod in an efficient and inexpensive manner. The piston includes a threaded interior which is secured to a corresponding threaded portion on the end of the piston rod. An opening through a portion of the piston is aligned with a recess within the end portion of the piston rod to permit the insertion of a locking pin into the aligned openings. Thereafter, a compression ring, which is pivotally attached to the locking pin, is slipped into a complementary groove that is provided on the exterior periphery of the piston end portion. This provides a positive connection between the rod and piston which tolerates dimensional variations and eliminates play.