Duff-Norton Screw Jacks

Duff-Norton has manufactured screw jacks since 1883 and offer a variety of screw jack types including ball screw jacks and machine screw jacks.

When comparing the two screw jack types at the same capacity level, ball screw jacks, being much more efficient, require less motor horsepower to move the same load than do the equivalent machine screw jacks.

However, many machine screw jacks are inherently load holding, offer a broader capacity range and a greater selection of special features or materials. Machine screw jacks are often favored in applications subject to constant vibration.


Machine Screw Jacks

Machine screw jacks can be used to push, pull, and apply pressure as linear actuators. They are furnished with standard raises in increments of one inch. Depending upon the size and type of load, models are available with raises up to 20 feet.

Duff-Norton worm gear screw jacks can be operated manually or by means of gear motors. The machine screw jack models can be used singly, in tandem or in multiple arrangements. Since most capacities of mechanical screw jacks have a uniform lifting speed, added economy can be realized in raising unevenly distributed loads by operating the different capacities in unison.

Look inside the machine screw jack design and its features:

  • Positive, mechanical positioning
  • Uniform lifting speed
  • Multiple arrangements
  • Anti-backlash (optional)

Duff-Norton machine screw jacks are produced in many standard models with a wide range of capacities, there is a standard model for almost any requirement. Models can be furnished to 350 Tons capacity. Browse all our available dimensions or reach out to an engineer to discuss the needs of your application.

Ball Screw Jacks

Ball screw jacks feature a low friction ball screw and nut design resulting in longer life at load and requiring less power to achieve a specified thrust.

Look inside the ball screw jack gearbox where the ball nut is equipped with return tubes for continuous recirculation of alloy steel balls. Main features of a ball screw lift include:

  • Move loads and apply force more efficiently than other mechanical actuators
  • Permit faster operation and longer life under load
  • Requires less power by reducing screw friction
  • Permit synchronization of multiple units
  • Capacity from ½ to 50 tons
  • Handles full load tension or compression

Browse available configurations, dimensions and more of our available ball screw jacks. Or reach out to an engineer to discuss your specific application needs.

Download the Duff-Norton Screw Jacks Design Guide at right >>