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Machine Screw Jack

Standard model capacities from 1/4 ton to 100 tons. Metric capacities from 5 kN to 200 kN.

The Inch and Metric Worm Gear Machine Screw Jacks incorporate an alloy or stainless steel worm which drives a high strength bronze worm gear (drive sleeve). The worm shaft is supported on anti-friction tapered roller bearings with external seals provided to prevent loss of lubrication. The drive sleeve is supported on anti-friction tapered roller or ball thrust bearings. 

  • Low noise (no rolling components)
  • Ideal for vertical and light loads
  • Pre-loaded nut assembly reduces backlash
  • Safe for static loads
  • Lower cost
  • Use individually or in multiple screw jack arrangements
  • Premium finishes are available including Epoxy, Outdoor, Marine, or per customer specification.

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Screw Jack Product Selector

Select the right product based on your specifications. 

Machine Screw Jack Engineering Resources

Inch Machine Screw Jacks

  • No "standard" travel lengths (built to specification). 
  • Ductile iron housings proportioned to support the rated capacity of the unit. 
  • Alloy steel worm drive with high strength bronze worm gear (drive sleeve).
  • Anti-friction tapered roller bearings with external seals to prevent loss of lubrication.
  • The drive sleeve is supported on anti-friction tapered roller or ball thrust bearings.

Part Number Reference

Inch Machine Screw Jacks

The jack housing is made of ductile iron and proportioned to support the rated capacity of the unit. The lifting screw is made of alloy steel with a minimum tensile strength of 95,000 psi.

  • Precision formed threads, typically using Class 2-C (Centralizing) tolerances.
  • Jack lift shaft lead tolerance is approximately ±0.004" per foot. 
  • Gear rations between 20:1 and 32:1 are self-locking and will hold loads without backdriving in the absence of vibrations. All other ratios may require a brake to prevent backdriving.

 

TRANSLATING SCREW JACK

A lift shaft moves through the gear box and extends out from the top or bottom. Integrated nut and worm gear for synchronized rotation. When the lift shaft is held to prevent rotation, it moves linearly through the gear box to move the load.

ROTATING SCREW JACK

A lift shaft moves a nut as it turns and is fixed to the worm gear and extends out the bottom or top of the jack. The load (attached to travel nut), moves along the lift shaft.

DOUBLE CLEVIS SCREW JACK

Moves a load through an arc, such as tracking antennas, hinged doors or air dampers. One clevis is mounted on the end of the lift shaft and the other clevis is welded to a heavy duty stem cover, which is welded to the housing.

KEYED SCREW JACK

Prevents rotation of the lift shaft with a square guide attached to the screw translating inside a square stem cover. The square stem tube is supplied with lube fittings. A lift shaft moves through the gear box and extends out from the top or bottom. An integrated nut and worm gear rotate together. When the lift shaft is held to prevent rotation, it moves linearly through the gear box to move the load.

ANTI-BACKLASH SCREW JACK

Used wherever reversible load conditions require precision positioning control. Adjustable backlash Machine Screw Jack models are available to reduce backlash to approximately 0.003".

 

Stainless Steel Machine Screw Jacks

Stainless Steel Machine Screw Jacks

All external components are manufactured from 300 series Stainless Steel materials. These jacks use a stainless steel worm with a high strength bronze drive sleeve.

 

Metric Machine Screw Jacks

  • No "standard" travel lengths (built to specification). 
  • Ductile iron housings proportioned to support the rated capacity of the unit. 
  • Alloy steel worm drive with high strength bronze worm gear (drive sleeve).
  • Anti-friction tapered roller bearings with external seals to prevent loss of lubrication.
  • The drive sleeve is supported on anti-friction tapered roller or ball thrust bearings.

Part Number Reference

Metric Machine Screw Jacks

The threads are precision formed, typically using Class 2-C (Centralizing) tolerances. Jack lift shaft lead tolerance is approximately ±0.004" per foot. Worm Gear Machine Screw Jacks having gear rations between 20:1 and 32:1 are self-locking and will hold loads without backdriving in the absence of vibrations. All other ratios may require a brake to prevent backdriving.

Related Machine Screw Jack Products

 

 

Start with a base machine screw jack and add accessories to configure a complete machine screw jack system.

 

Nook Industries offers a wide assortment of machine screw jack accessories to accommodate specific applications. From motor mounts to limit switches to lubricant, Nook can easily configure a complete screw jack system.

 

Explore Jack Accessories

Complete Screw Jack Lift System with AC Motor, Gearboxes, Shafting, and Couplings