ramscrew

A ramscrew is a term used in some engineering contexts to describe a screw mechanism that produces linear movement of a ram, a sliding block or piston, within a machine. In its basic form, a ramscrew consists of a threaded shaft and a nut or nut-like bearing attached to the ram. When the screw is rotated by a drive such as a hand wheel or an electric motor, the threads convert rotary input into axial motion of the ram, enabling lifting, pressing, or positioning against a load.

Design and variants commonly involve lead screws with square, trapezoidal (ACME), or ball-thread profiles. Materials are typically steel, with surface treatments to resist wear. Lead screws offer simplicity and self-locking behavior, which helps prevent back-driving under moderate loads. Ball screws, by contrast, provide higher efficiency and smoother motion at the expense of greater complexity and cost. The thread pitch and start count affect travel per turn and speed, while multi-start configurations increase rapidity of movement.

Applications and context vary; the term ramscrew is not standardized and in many cases the same device is described as a screw jack, lead screw, or linear actuator. Uses include small presses, lifting jacks, machine tools, and precision positioning stages. Maintenance focuses on proper lubrication, alignment of the screw and nut, and monitoring wear in the threads to maintain accuracy and safety.